ZR-1 Net Registry Forums  

Go Back   ZR-1 Net Registry Forums > C4 ZR-1 > C4 ZR-1 Technical Postings

Reply
 
Thread Tools Display Modes
Old 08-12-2021   #21
32VALVS
 
32VALVS's Avatar
 
Join Date: Sep 2020
Location: IA
Posts: 11
Default Re: intermittent problem - car starter dead, no start

I fought the hot no start (with solenoid click) condition in my '92 this spring.

I had a solid "click" from the solenoid and assumed it must be the battery, it was weak after winter storage. That didn't fix it and left me bump starting in the grocery store parking lot.

New contacts fixed it for a few days. Then back to the clicking no-start.

Hmm...pulled the plenum and put in a new starter. Thought maybe the windings were shorted when hot.

Same problem, stranded at a friend's house until it cooled.

Jumped the wires at the clutch switch and have not had another issue all summer.

The switch measured 0.5 ohms resistance. That's equivalent to 300 feet of 12 AWG copper wire!

The switch had enough voltage/current drop that it actuated the solenoid with enough force to click, but not enough force for the contacts to pass the battery current needed to turn the hot starter.

Last edited by 32VALVS; 08-12-2021 at 08:39 PM.
32VALVS is offline   Reply With Quote
Old 08-13-2021   #22
mlipmd
 
Join Date: Mar 2021
Location: Crawfordville, FL
Posts: 216
Default Re: intermittent problem - car starter dead, no start

I tried a few times to post this here but keep getting timed out so I'm just copying what I posted on the C4 ZR-1 section of the Corvette Forum.

For those of you that have followed these threads, here's a new better way to fix this problem.
Twice now I got the DNS, both times parked in a shopping area parking lot. Had to wait 30-45 'min. till the car cooled off then it would start right up like it never happened. PIA as well as embarrassing.
I have been reading a lot about this on this and the ZR-1registry forum and the best advice is to modify my '90 to the later '93-95 ignition system by bypassing the CSS and installing a relay to power the starter solenoid.
All of the relay mods talk of finding the purple wire in the wiring loom and cutting it, using the CSS end of the wire to trigger the relay, and the output goes to the other end of the wire, used to power the starter solenoid.Cutting wires is scary, but there is a much easier,better way without cutting any wires.
If you take down the DS dash panel to gain access to the CSS wiring preparing to bypass it, the first thing you will immediately see is the light yellow with ? blue or black stripe wire (wire looks white, so from now on whatever color it really is, I'm calling it "white" because it looks white to me), alongside a purple wire, in a black connector, connected to 2 black wires leading up higher to the CSS above the clutch pedal.
Don't go looking for the CSS itself, it's buried way up underneath the dash and you don't need it for anything.
If you take apart that connector you have the ends of the white wire from the ignition switch and the purple wire leading out to the starter solenoid. If you just want to bypass the CSS, just connect a short jumper wire to the 2 male terminals in that plug. But if you want to do the starter relay mod, why would you want to dig around in a wire loom and look for the purple wire and cut it for your relay connections? You have the end right there.
Very simply, use the white wire to trigger the relay, use the purple wire for the output to the starter solenoid, all by very simply attaching a short jumper wire to each in the male plug in the connector.
So when my 60-80 amp heavy duty relay arrives tomorrow, I am going to plug in a new 12V hot lead to pin 87, the purple lead connected via a short jumper in the connector plug to 30, the white lead (from the ignition switch) via a short jumper in the connector plug to 86, and a ground from somewhere under the dash, to a bolt handy, to 85. Very simple, no searching for a purple wire to cut, less connections, less resistance in the circuit, and much easier. In addition the whole thing is hidden under the dash, out of the weather, out of the heat, out of sight. Also, if I ever want to restore it back to original, all I have to do is pull off a few jumpers and hook it back up the way it was, no repairing cut wires.
The only thing I have to figure out is how to run the 12V hot lead into the cabin. I can enter via the driver's door accordion, poke a small hole in the bottom and then silicone it up, I can enter via the grommet that the hood latch release cables pass through, also poking a hole then siliconing it up, or I can run a lead down in front of the door hinges protecting the wire inside a 1/4"vinyl tubing and lead it right into the cabin. I already checked and there is plenty of room as the door closes and nothing would get squished but that would be pretty unsightly and not very professional.
Tomorrow if I get to this I'll post some pics but this seems to me very much easier and less destructive and easily reversible if you want.
Hopefully after this I'll never have that DNS happen to me again.

Last edited by mlipmd; 08-13-2021 at 06:58 PM.
mlipmd is offline   Reply With Quote
Old 08-15-2021   #23
mlipmd
 
Join Date: Mar 2021
Location: Crawfordville, FL
Posts: 216
Default Re: intermittent problem - car starter dead, no start

For a wiring diagram and pics of what I did, go here, post #8.
https://www.corvetteforum.com/forums...post1603877386
mlipmd is offline   Reply With Quote
Old 08-15-2021   #24
Matt B
 
Matt B's Avatar
 
Join Date: Jan 2021
Location: Beautiful Bavaria
Posts: 523
Default Re: intermittent problem - car starter dead, no start

Thanks for that. Staying inside the cabin seems useful considering heat an moisture under the hood.
I cut the purple wire during a plenum pull as it's VERY easy to locate inside that remote end branch of the harness. One could even use a matching pigtail to connect the terminal end of the wire to that pigtail instead of the starter connector.
However, precondition is to remove the plenum and dig under the coil base plate.
In any way I like your approach more...

Sent from my SM-G991B using ZR-1 Net Registry mobile app
__________________
ZR-1 #638/1991
Matt B is offline   Reply With Quote
Old 10-08-2021   #25
karlaw
 
Join Date: Jun 2008
Location: Alberta
Posts: 85
Default Re: intermittent problem - car starter dead, no start

Thanks


Sent from my iPhone using ZR-1 Net Registry
__________________
LT5
karlaw is offline   Reply With Quote
Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 05:22 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright ZR-1 Net Registry 2020