Maybe Clutch Switch?

[TX '90 ZR1]

Drove the car a couple of days ago and parked it in the shop. I needed to move it to a different area so jumped in to start it. Nothing. Never had an issue before with starting.
Battery is full charge, security appears to be OK. When I turn the key to start position, the radio and AC control displays dim. This happens whether I have the clutch pushed down or not. Verified full clutch pedal travel.
I'm starting to do my FSM research and also checking the threads here. Just thought I'd throw this out for ideas from the knowledegable people here on the forum.
Oh, it's a '90. 35k on the miles.
:confused:

[jss06c6]

How old is the battery? Do you have a charger that you can use? To verify a good battery requires a load test, not just a voltage check.

Sent from my XT1585 using ZR-1 Net Registry mobile app (http://r.tapatalk.com/byo?rid=90383)

[Paul Workman]

Well, the starter makes a pretty good impromptu "load tester". Anything under 10 VDC across the battery terminals after 10 sec of cranking WHILE cranking = weak battery and the charging system (if and when the car starts again) should be checked to see approx 14.7 volts (cold engine and discharged battery).

From a paper by Marc Haibeck, (below) the 90-92 starting schematic WITH typical voltage readings at the various test locations. (See ZR'1 Specialist (http://www.zr1specialist.com/) for complete article)

AND, a schematic of an auxiliary start relay modification that can be installed to relieve the high current load (and subsequent high wear rate) of the clutch safety switch.

[TX '90 ZR1]

How old is the battery? Do you have a charger that you can use? To verify a good battery requires a load test, not just a voltage check.

Sent from my XT1585 using ZR-1 Net Registry mobile app (http://r.tapatalk.com/byo?rid=90383)

Battery is less than a year old. Load tests good. Hooked up charger on boost and still same results.
:confused:

[TX '90 ZR1]

Well, the starter makes a pretty good impromptu "load tester". Anything under 10 VDC across the battery terminals after 10 sec of cranking = weak battery and the charging system (if and when the car starts again) should be checked to see approx 14.7 volts (cold engine and discharged battery).

From a paper by Marc Haibeck, (below) the 90-92 starting schematic WITH typical voltage readings at the various test locations. (See ZR'1 Specialist (http://www.zr1specialist.com/) for complete article)

AND, a schematic of an auxiliary start relay modification that can be installed to relieve the high current load (and subsequent high wear rate) of the clutch safety switch.

Paul, not getting any clicking anywhere like it is trying to engage the starter. Same result w/ battery charger on boost. Battery load tests good.:confused:
I have never noticed, but is is correct for the radio and AC display lights to dim when turning the key to start position? Mine are dimming either with the clutch pedal down or not.

[TX '90 ZR1]

Got started troubleshooting. Here's where I am and need ideas.
With key in the start position the security light stays on steady. According to Marc's troubleshooting write up, this indicates the VATS system is shutting everything down.
Checked codes and get a big H53 after a small 1.-(nothing after the 1.)
Also get a big H46 after a small 4.-(nothing after the 4.)
Went to the FSM and code 53 has to do with the pass key. Followed instructions to read value as instructed in step 1. The number I get is 255.
After this I am getting lost. They are mentioning an adapter from J 35616.
I see no reference to code 46 in the CCM section. Code 46 in the ECM section refers to injector shut down. Could this be what I am seeing?
Anyone have any ideas or input?

[TX '90 ZR1]

Did not get to spend a lot of time on it today.
Here's what I did accomplish.
Checked ECM codes and am getting a #46 which refers to the pass key just like the #53 on the CCM. This tells me the issue is definitely in the VATS system?
Tried second ingnition key, but still same result.
Will try to get time over the weekend to figure out the additional troubleshooting steps in the FSM.
I'll post what I find, but still open for suggestions.

[Flyman 27]

The wire from the key switch which carries the key code (resistance) to the VATS system is fairly fragile. It is the orange 2 lead wire. You can check the resistance between the 2 leads on the plug at the harness. It is on top of the lower steering column. This will tell you quick if the key switch is working. Cycle the key switch while checking the resistance.

[QB93Z]

You said that the with the key in START, there is no cranking but the interior lighting dims. Is that correct?

To me that indicates that the starter circuit is energizing the starter coil, but the starter contacts at the coil are not energizing the starter motor. If VATS or clutch switch was not correct, there would be no voltage drop with key in START.


Although, the Codes you are getting are curious. Have you tried push starting the car?


Jim

[TX '90 ZR1]

Thanks for the input guys. Any other thoughts would be appreciated.
To sum up the scenario:
Car was driven 5 days ago. Everything working correctly. Made several stops with normal shutdown & restart. Return to shop and park car. After sitting 2 days unlocked with key out of ignition, car does not attempt to start.
Security light blinks with car at rest w/doors unlocked. (Normal)
Set security system and simulate brake in, horn sounds. (Normal)
Insert key in ignition switch and turn to "on" or "start". Security light goes to steady and does not go out after a couple of seconds. (Not Normal)
When key is turned to "start" position, displays for the radio and A/C control dim. Nothing else dims, volt guage does not move, and draw on system does not appear to increase. ( Not sure if the displays, radio and A/C, dimming is normal or not).
Turn key to "lock" and remove. Security light goes back to blinking. (Normal).
CCM code #53 set. (Pass Key Detection Circuit)
ECM code #46 set. (Pass Key Circuit).
Per FSM, code #53 troubleshooting, value of 255 obtained @ display 1.2 , lower reading of 06. (06255).
This, as best I can figure, is pointing to the lock cylinder wiring.
Guess I will get to the connectors on steering column and check.
I have not attempted to push start car. With all the above indications, I would assume the injectors are shut down?
I had been thinking about what to do to the car next. Guess I found it!!
Any more detailed information about bypassing the VATS if I need to go that way for a while? Marc mentions about jumping a switch, but have not seen any detailed instructions.
Please everyone, continue to throw me ideas. I will keep everyone posted on progress.

[A26B]

Several years ago, there was a similar incident & the owner went through literally everything. It turned out to be a bad battery terminal connection. They were loose, cleaned, tightened & all was good.

[TX '90 ZR1]

Several years ago, there was a similar incident & the owner went through literally everything. It turned out to be a bad battery terminal connection. They were loose, cleaned, tightened & all was good.

Thanks Jerry,
I know the connections are tight, but have not cleaned the positive since battery was installed about a year ago.
Before I start tearing out the under dash, think I'll disconnect the battery and see. Best to eliminate all the easy, simple stuff first.
By the way, someone mentioned to clean the key. Did that to no avail.
Really appreciate your input.:)

[zrfast1]

Do yourself a favor...bypass the clutch switch.

[TX '90 ZR1]

OK.
Cleaned battery connections and re-installed. This did not fix the problem, but the positive terminal did need cleaning.
Gained access to under the driver's side dash.
As suggested by Flyman 27, located orange sleeve with 2 small white wires in it. Disconnected connector and checked for readings between the two wires going into the steering wheel housing. There is no difference in the reading whether key is in place or not, and irrespective of the key position. There is no resistance indicated.
I decided to test the individual wires to ground. One of the wires shows continuity to ground. I have not checked the schematic yet, but I would not think one of these wires should be grounded.
I am going to continue following the FSM procedure, but I am thinking that this wire being grounded may be an issue?
Feedback Please.
Thanks Guys.

[QB93Z]

I have worked on two ZR-1's that had a ground problem related to the wiring under the dash and the steering column harness. The symptoms didn't match your current problem but were very perplexing.


There are two electrical ground connections on the back of the block. Once again I don't know that this is related to you symptoms but may be worth checking. The grounds each have multiple ground wires on a bolt into the back of the block. They are hard to see but the guide is to look above the bell housing bolts on the top right and top left of the bell housing to block connection. On some cars, the left side ground bolt can be reached from above by reaching down below the area of the PCV valves and feeling around the back of the block.


Jim

[5ABI VT]

This happened to me when I was bringing the car home after moving. No prior no start ever. Happened at the gas station on the way home out of all places and times. I ended up push starting it and got it home. Later found out it was the clutch switch. I bypassed it eventually after tinkering with another plug I mistakenly thought was the clutch switch and it solved the problem.

[TX '90 ZR1]

Thanks for the reply Guys.
I will see if I can get to the ground points and check them. Also, I intend to take a look at the clutch switch while I am in there. With the codes I am seeing, it does not "appear" to be the cause of the current issue.

[TX '90 ZR1]

Had a chance this afternoon to do a little more troubleshooting.
Refer to the attached page from FSM to follow my progression.
Code #53 is set on the CCM which indicates either circuit open or shorted to B+.
By following the diagnosis chart I come to a short in circuit #1073. (See Chart)
Is this telling me that the wire in the steering column is shorted and needs repair? To get there I will need to pull the steering wheel and want some back up before I do that.
Also, refer to my post of earlier today about readings I got from wires in steering column.
I'm going to wait for some feedback before I go any further.
Appreciate everything
!8355

8356

[TX '90 ZR1]

Still trying to figure this out.
Everything keeps pointing to the key lock cylinder or the wires going to it.
I checked the battery connections as suggested.
I checked the clutch switch as suggested.
I cleaned the key contacts in the lock cylinder with electrical contact cleaner.
Cleaned both keys. Both keys have the same resistance and the symptoms do not change no matter which key is used.
Cleared, or attempted to clear, codes in the CCM and ECM. They do not go away. The codes are there next time I turn the key on. I guess this would make sense as the codes are probably being set as soon as the key is turned?
I am now getting some resistance through the two wires going into the column to the key cylinder when key is inserted in the lock position. With meter set to the 2k position, the reading in the lock position is 1.876. This is the same reading I get when checking the keys. The resistance goes away when I move the key away from the lock position. I would think the resistance should be present in all locations??????
Feedback, suggestions please.

[Flyman 27]

A year ago I was having a similar problem, it turned out to be the resistor readings in the connector to the key, that wasn't too hard to replace (videos on YouTube).

This past spring I was having another no start issue that I was totally lost on. -=Jeff=- came by and after checking connectors & switches, jumpered over the clutch switch and it started right up with no issues since.

Maybe -=Jeff=- can pipe in here and tell you where the connector is and what wires you jumper. The Conn was on the LH side, under the Driver's side hush panel. I didn't see where the conn was from, so I can't help you there. -=jeff=- was very systematic in his approach and saved me hours & hours of a frustrating problem I couldn't chase.

[-=Jeff=-]

OK.
Cleaned battery connections and re-installed. This did not fix the problem, but the positive terminal did need cleaning.
Gained access to under the driver's side dash.
As suggested by Flyman 27, located orange sleeve with 2 small white wires in it. Disconnected connector and checked for readings between the two wires going into the steering wheel housing. There is no difference in the reading whether key is in place or not, and irrespective of the key position. There is no resistance indicated.
I decided to test the individual wires to ground. One of the wires shows continuity to ground. I have not checked the schematic yet, but I would not think one of these wires should be grounded.
I am going to continue following the FSM procedure, but I am thinking that this wire being grounded may be an issue?
Feedback Please.
Thanks Guys.


Sounds like a VATS issue with the key.. you found the orange wires coming from the column, measured across them with no key, you should have no resistance. According to your info this is good

Now you added the key, but still got no resistance, this is not good. next steps (if it were me)

- measure across the pellet in the key and note the resistance
- find a place that you can purchase resistors and build a bypass
- put the bypass on the car side and see if it starts.

You could also test a second key if you have one, or get a new key made.

Here is the VATS code chart:
Key #1 = 0.41 K Ohms resistance
Key #2 = 0.53
Key #3 = 0.68
Key #4 = 0.89
Key #5 = 1.13
Key #6 = 1.47
Key #7 = 1.87
Key #8 = 2.37
Key #9 = 3.02
Key #10 = 3.73
Key #11 = 4.76
Key #12 = 6.05
Key #13 = 7.47
Key #14 = 9.55
Key #15 = 11.76


After this, if there is still issues, next is to by-pass the clutch switch to test it

[TX '90 ZR1]

A year ago I was having a similar problem, it turned out to be the resistor readings in the connector to the key, that wasn't too hard to replace (videos on YouTube).

This past spring I was having another no start issue that I was totally lost on. -=Jeff=- came by and after checking connectors & switches, jumpered over the clutch switch and it started right up with no issues since.

Maybe -=Jeff=- can pipe in here and tell you where the connector is and what wires you jumper. The Conn was on the LH side, under the Driver's side hush panel. I didn't see where the conn was from, so I can't help you there. -=jeff=- was very systematic in his approach and saved me hours & hours of a frustrating problem I couldn't chase.

Flyman 27.
Do you think I should see resistance through the wires going to the lock cylinder no matter the position of the key? After cleaning the cylinder contacts as best I could I am getting resistance in the "Lock" position, but I am not getting any as I move the key to other positions.
In your first scenario above, do I understand correctly that you replaced the key lock cylinder?
Thanks for the reply. Notice Jeff has replied also. Will respond to his suggestions as well.

[-=Jeff=-]

Flyman 27.
Do you think I should see resistance through the wires going to the lock cylinder no matter the position of the key? After cleaning the cylinder contacts as best I could I am getting resistance in the "Lock" position, but I am not getting any as I move the key to other positions.
In your first scenario above, do I understand correctly that you replaced the key lock cylinder?
Thanks for the reply. Notice Jeff has replied also. Will respond to his suggestions as well.

We rebuilt Flyman's column and he used a new cylinder and keys..

[Mr Blue]

Without the key in, should it not be infinite resistance? The pellet in the key is the resistor. I had this problem, and solved it by bypassing the key switch with a resistor soldered in the circuit.

[-=Jeff=-]

Without the key in, should it not be infinite resistance? The pellet in the key is the resistor. I had this problem, and solved it by bypassing the key switch with a resistor soldered in the circuit.

Correct and according to his post, he read no resistance (infinite) without the key installed

[TX '90 ZR1]

Jeff, Mr.Blue & Flyman 27.
Really appreciate you helping me out with this.
I am out of my element with electrical issues. My mechanical background is mostly aviation related, but I always had someone to holler at when the electrical stuff came up.
Looks like we are narrowing it down to an issue with the contacts in the key switch. As I stated, I cleaned the contacts with electrical cleaner as best I could yesterday. This is when I started getting resistance with the key in the lock position only. Just checked again and there is intermittant resistance when in the on position, but the resistance goes away if I move it any further.
Both of my keys check to be a #7. This corresponds to the resistance I get when I do get a reading through the wires.
I think I will get a resistor set up to bypass the key switch and give that a try.
I probably need to change the switch anyway. It is a little "quirky" when operating it. Does not operate smoothly.
A question on code erasing if someone would jump in.
To erase the CCM code that shows on the speedo display, is it the same procedure as with the other systems? (Ground appropriate pin, turn key on, release for 3 seconds, re-ground for 3 seconds, release and turn key off after 10 seconds)
Thanks again guys.

[-=Jeff=-]

I believe the CCM codes will move to history on their own when they are no longer present. Otherwise I would refer to the Factory Service Manual

[TX '90 ZR1]

I believe the CCM codes will move to history on their own when they are no longer present. Otherwise I would refer to the Factory Service Manual
Thanks Jeff.

[TX '90 ZR1]

I believe the CCM codes will move to history on their own when they are no longer present. Otherwise I would refer to the Factory Service Manual

I found this on clearing CCM codes. Thought I would share.:handshak:

Clearing the CCM codes can be done after the automatic sequence of codes has occurred with the following instructions:

Press the TRIP RESET button until “1.0” is displayed in the module number area. Then press the TRIP/ODO button until “1.7” is displayed in the module number area. Once there, press and hold the ENG/MET button until “—“is displayed. This will clear any CCM codes. After “—“ is displayed, turn the key off, wait ten seconds, turn the key back on and check for any CCM codes.

[-=Jeff=-]

Yeah, that was in the FSM right? I was quite sure it was there

[TX '90 ZR1]

Yeah, that was in the FSM right? I was quite sure it was there

You are correct Jeff. It is in the FSM and there are some explanations available by doing a Google search.

[-=Jeff=-]

any more progress?

[TX '90 ZR1]

any more progress?

Not yet. My plan is to come up with something to simulate the key resistance and plug it into the key lock harness.
Just need a little time, which I have been short of the last couple of days, to chase down what I need to rig it up.
Main problem is that I am a little farther than in the middle of nowhere from anywhere!! :-D:-D:-D
I'll figure something out and keep everyone updated.

[Paul Workman]

A year ago I was having a similar problem, it turned out to be the resistor readings in the connector to the key, that wasn't too hard to replace (videos on YouTube).

This past spring I was having another no start issue that I was totally lost on. -=Jeff=- came by and after checking connectors & switches, jumpered over the clutch switch and it started right up with no issues since.

Maybe -=Jeff=- can pipe in here and tell you where the connector is and what wires you jumper. The Conn was on the LH side, under the Driver's side hush panel. I didn't see where the conn was from, so I can't help you there. -=jeff=- was very systematic in his approach and saved me hours & hours of a frustrating problem I couldn't chase.

OP: Jeff's method of methodically troubleshooting is THEE way to solving electrical issues systematically. =D> It's fine to have a number of suggestions of things to check, but randomly "stabbing in the dark" is no substitute for efficient, logical circuit tracing and verification along the way. Ya don't wanna go down that path, IMO.

[TX '90 ZR1]

OP: Jeff's method of methodically troubleshooting is THEE way to solving electrical issues systematically. =D> It's fine to have a number of suggestions of things to check, but randomly "stabbing in the dark" is no substitute for efficient, logical circuit tracing and verification along the way. Ya don't wanna go down that path, IMO.

Thanks Paul,
That is what I am trying to do. I have followed the FSM trouble shooting and intend to verify before randomly changing parts.
I have checked things that were suggested, but with the codes I am getting and the FSM procedure telling me it is in the key lock circuit, I am going to follow this path until it is either verified or proven incorrect.
All I have in it to this point is my time which is generally not worth much!!
:cheers:

[TX '90 ZR1]

This one has been a journey!!
All the indications I was getting from codes and tests indicated the key lock circuit in the steering column. Followed the FSM troubleshooting chart. Sometimes I would get a higher voltage reading than recommended, so chased that side also. This was a slight discrepancy. ie: 5.2v vs 5.6v.
As I could not source something to make a resistor out of locally, I had to order what I needed. Got it and verified correct resistance for my car. Hooked this up and still had the same issue. What the hell? Security light still stays on steady and I can't get the code to go away in the ECM. The CCM codes cleared.
At this point I am trying to find enough hair on my head so I can pull it out!!!
Looks like I'm on my own now, so start checking all of the security system components. I started by trying to remember anything I had done to the car recently that might affect this. I had cleaned the inside of the rear glass and a defroster wire came loose. I had reconnected it. This did not sound like a security issue, but checked anyway.
Had also cycled the door locks while checking the security system operation. Everything in the drivers door checked OK. BUT, and here it is!!! The passenger door lock was not making good contact.
Who would have thought??
Anyway, it is operating properly now. Now I can go on to doing little picky things to it and not have nightmares about wiring schematics.
:cheers:

[zrfast1]

.....well Ill keep that in the memory banks. Good for you. Now enjoy the car...you earned it.

[TX '90 ZR1]

.....well Ill keep that in the memory banks. Good for you. Now enjoy the car...you earned it.

Thanks. I think any tidbit of information is worth storing in the memory bank. Whenever I run across something I try to post it for others use. I know I scour the threads for information so turn about is just good manners.
To be clear, the initial no-start issue was the key lock cylinder in the column. Erratic resistance readings. I still have it bypassed and will change it sometime. The passenger door lock issue arose while in the midst of troubleshooting the original problem. It did not raise it's ugly head until I had eliminated the original problem.
:cheers:

[zrfast1]

Thanks. I think any tidbit of information is worth storing in the memory bank. Whenever I run across something I try to post it for others use. I know I scour the threads for information so turn about is just good manners.
To be clear, the initial no-start issue was the key lock cylinder in the column. Erratic resistance readings. I still have it bypassed and will change it sometime. The passenger door lock issue arose while in the midst of troubleshooting the original problem. It did not raise it's ugly head until I had eliminated the original problem.
:cheers:
You mentioned your background is in aviation. I (we) see this everyday as everything is not what it always seems to be. Apply troubleshooting techniques
and just when you think you have it, you dont. Been there many times. At least it showed its ugly face when you corrected the main issue. Broken wires are the worst..at least you didnt have that! Cheers

[TX '90 ZR1]

You mentioned your background is in aviation. I (we) see this everyday as everything is not what it always seems to be. Apply troubleshooting techniques
and just when you think you have it, you dont. Been there many times. At least it showed its ugly face when you corrected the main issue. Broken wires are the worst..at least you didnt have that! Cheers

Yes, most of my mechanical background is in aviation. I have the A&P and used to have the IA, but mostly I was the "guinea pig" that got to test the limits and try to make them break! As I say, and others as well, " Flying is hours upon hours of boredom interrupted by moments of sheer terror!".
Here's a pic of one of my Reno races.
8408
:cheers:

[Dynomite]

Great Photo.....thanks Kenny :thumbsup:

https://cimg0.ibsrv.net/gimg/www.corvetteforum.com-vbulletin/800x600-1/80-air_race_bea5176463d88840f6628cdf50da3676892c69ad. jpg


OOPS! I got distracted :p

[zrfast1]

Yes, most of my mechanical background is in aviation. I have the A&P and used to have the IA, but mostly I was the "guinea pig" that got to test the limits and try to make them break! As I say, and others as well, " Flying is hours upon hours of boredom interrupted by moments of sheer terror!".
Here's a pic of one of my Reno races.
8408
:cheers:

....And every landing is just a controlled crash.....if you can walk away ..its a good one. Lol
Great pic

[djhome23]

Thanks. I think any tidbit of information is worth storing in the memory bank. Whenever I run across something I try to post it for others use. I know I scour the threads for information so turn about is just good manners.
To be clear, the initial no-start issue was the key lock cylinder in the column. Erratic resistance readings. I still have it bypassed and will change it sometime. The passenger door lock issue arose while in the midst of troubleshooting the original problem. It did not raise it's ugly head until I had eliminated the original problem.
:cheers:
I want to say THANKS in a big way for this thread. Just spent 3 months getting my 1993 back to a respectable shape. Basically it was delivered to me and I went to town on it. Didn't even put 1 mile on it.
Pictures here: dbgolf23.wix.com/1of1

But anyway back to my THANKS! I just finished everything other than the brakes and my 1993 was doing the same thing. Turn the key - NOTHING no crank...no security light...nothing but a slight dim like it was going to try to start - Now I have had the battery disconnected and reconnected as I went through the all the lights in the car. Bought a new Odyssey battery and still nothing.
Came to this thread and decided to just try the lock and unlock of the doors, shut them and open them a couple of times and again lock and unlock. Car fired right up!!!! No issues. So THANKS for posting these types of threads and keeping them here for all of us newer members to get some help!

[TX '90 ZR1]

I want to say THANKS in a big way for this thread. Just spent 3 months getting my 1993 back to a respectable shape. Basically it was delivered to me and I went to town on it. Didn't even put 1 mile on it.
Pictures here: dbgolf23.wix.com/1of1

But anyway back to my THANKS! I just finished everything other than the brakes and my 1993 was doing the same thing. Turn the key - NOTHING no crank...no security light...nothing but a slight dim like it was going to try to start - Now I have had the battery disconnected and reconnected as I went through the all the lights in the car. Bought a new Odyssey battery and still nothing.
Came to this thread and decided to just try the lock and unlock of the doors, shut them and open them a couple of times and again lock and unlock. Car fired right up!!!! No issues. So THANKS for posting these types of threads and keeping them here for all of us newer members to get some help!

As I have mentioned several times: The cost of admission is only a drop in the bucket as compared to value received. If you own or are interested in C4 ZR-1's, you MUST be a member of the "Registry" !!!
=D>=D>:cheers:

[djhome23]

As I have mentioned several times: The cost of admission is only a drop in the bucket as compared to value received. If you own or are interested in C4 ZR-1's, you MUST be a member of the "Registry" !!!
=D>=D>:cheers:
AMEN BROTHER!