Anybody ever replace the clutch safety switch?

[Z51JEFF]

I'm having issues with the dreaded no start again so decided it's time fix the damn thing once and for all. I've got an NOS switch so that's not the problem,the problem is getting it out of the car. And I thought getting the CDM controller out of the car was a job,this things got it beat.

[Tony Davila]

I by-passed mine, it has been that way for years. I will fix it correctly in the future and yeah it is up there. You need Pray mantis hands to do it.:-D

[We Gone]

Been looking for a switch for some time now so I have not done the clutch safety switch yet but I just did the CDM, can you say 3 hours but that counts I got it all in the first time and had inadvertently flipped it over (maybe something to do with working upside down). After I was done I thought I was going have to call the wife to drag me out lol. I will say it was well worth it I also had the I-Pod hook up added. Good Luck

[Z51JEFF]

Been looking for a switch for some time now so I have not done the clutch safety switch yet but I just did the CDM, can you say 3 hours but that counts I got it all in the first time and had inadvertently flipped it over (maybe something to do with working upside down). After I was done I thought I was going have to call the wife to drag me out lol. I will say it was well worth it I also had the I-Pod hook up added. Good Luck

The safety switch is pretty much the same deal. I just might by pass it, nobody drives the car but me but don't like the idea of having something that doesn't work. On a positive note I'm starting to think the starter is the cause of the no start issue. The last time the car wouldn't start I could hear the starter relay energizing. If the switch kept the circuit open there shouldn't be any power to the starter relay,correct?

[XfireZ51]

I by-passed mine, it has been that way for years. I will fix it correctly in the future and yeah it is up there. You need Pray mantis hands to do it.:-D

Agree w Tony. I did this on my 84 sometime ago. What a PITA. If attempting,I highly recommend removing the driver's seat. When I got Roza Nero I bypassed the switch. I depress the clutch as a matter of habit together with always putting the trans in Neutral.

[Paul Workman]

I by-passed mine, it has been that way for years. I will fix it correctly in the future and yeah it is up there. You need Pray mantis hands to do it.:-D

I agree w/ Tony and Dom.

By-passed mine too, after the "dreaded no start" phenomenon occurred (foretold by some hesitations at first, followed by having to pump the clutch pedal, and then nothing I tried would work, short of replacing or by-passing it).

I learned to drive back in the dark ages when there were no clutch interlock switches; learned to always mash the clutch when starting - SOP (except for one time just recently where the hand was quicker than the foot - Ooops!)

By-passing the clutch interlock has the advantage of being able to bump the starter w/o having to push the clutch in first. Not a biggie, but occasionally the need arises in the course of maintenance (and not having someone to assist me). And, when would it be convenient for it to fail on you?

There is an "issue" regarding the clutch interlock switch as it is configured in the 90-92 cars* in that ALL of the starter solenoid current passe through that switch. (This will result in arching and thus damaging the contacts especially when the ignition switch is turn to START before the pedal gets depressed far enough to engage the switch (arching), AND especially when the opposite happens, where the pedal is inadvertently lifted before the START (key) is released.)

If one has a 90-92 with a functioning clutch interlock switch, and wishes to isolate that switch from the relatively high solenoid current, a relay can be installed behind the battery to carry the current load, and the clutch switch is only carrying the comparatively tiny current needed to activate the relay.

The supplemental starter relay mod for the 90-92 ZR-1s

http://i185.photobucket.com/albums/x220/6PPC_bucket/tech%20files/StarterRelay_zps748153c8.jpg (http://s185.photobucket.com/user/6PPC_bucket/media/tech%20files/StarterRelay_zps748153c8.jpg.html)

Marc Haibeck has an article on his ZR-1 Specialist (http://zr1specialist.com/HAT%20Web/articles/Diagnosing%20Starter%20Probems.pdf) website he wrote describing the two starter circuits with important test locations w/ voltages throughout the circuits.

[Z51JEFF]

On second thought my starter might it be the problem here. What I thought was the starter relay energizing was something else. Oh well, a bypass jumper is easier than pulling the plenum.

[RussMcB]

Jeff, is your dreaded no start condition: Cranking but not firing? Or not cranking at all?

[Z51JEFF]

Jeff, is your dreaded no start condition: Cranking but not firing? Or not cranking at all?

Not cranking. I'm going to replace the starter and bypass the clutch switch.

[Paul Workman]

Well, it's your money... But, IMO that is killing a fly with a sledge hammer!

Besides the clutch switch, the other bugaboo are the contacts and bridging "ring" in the solenoid.

I don't disagree w/ bypassing the clutch interlock, damn things can fail w/o warning, and I can think of lots of places that wouldn't be so convenient. (Besides, it is an unnecessary "nanny" measure when proper starting procedures are followed.)

As for the starter, R&R'ing the solenoid amounts to replacing the two "L" contact posts and using a little emery cloth to clean up the carbon tracing on the bridge ring. Voilah! Good as new for under $15 (got mine on ebay).

Once the clutch switch is by-passed, listen for a "click" at the starter when you roll the ignition key. If no "click" (of the solenoid), then check for voltage at the clutch switch first, and if necessary follow back to the starter relay, etc. (assuming fuses are all good).

From Marc Haibeck's paper...

93-95 MYs

http://i185.photobucket.com/albums/x220/6PPC_bucket/tech%20files/95starterviaHaibeck_zps4f96d5a3.jpg (http://s185.photobucket.com/user/6PPC_bucket/media/tech%20files/95starterviaHaibeck_zps4f96d5a3.jpg.html)

90-92 MYs

http://i185.photobucket.com/albums/x220/6PPC_bucket/tech%20files/90-92starter_zps9170e748.jpg (http://s185.photobucket.com/user/6PPC_bucket/media/tech%20files/90-92starter_zps9170e748.jpg.html)

FWIW, the solenoid contacts failed on my 90 at ≈ 40k miles, and the clutch switch at 57k miles (as a point of reference).

Good luck!

[Z51JEFF]

Paul,in one sentence you're telling me basically I'm wasting money replacing the starter and in the next you're telling me the starter is also troublesome,both of the no start issues I would like to address.Now here's where this thing gets completely bizarre. I've had this car for 8 years,I've put about 16,000 miles on the car in that time. Out of the 6 times the car wouldn't start 5 of those times the car was parked in the same spot at my parents house. Maybe I should park it across the street next I'm over there.

[Dynomite]

Paul,in one sentence you're telling me basically I'm wasting money replacing the starter and in the next you're telling me the starter is also troublesome,both of the no start issues I would like to address.Now here's where this thing gets completely bizarre. I've had this car for 8 years,I've put about 16,000 miles on the car in that time. Out of the 6 times the car wouldn't start 5 of those times the car was parked in the same spot at my parents house. Maybe I should park it across the street next I'm over there.

It might have something to do with the angle the starter Solenoid is sitting at :D
Is your parents house driveway level? :sign10:
Maybe there is an unknown high intensity magnetic field in that area. In which case...be very careful parking the car in the reverse direction as it may Start Itself ;)

[XfireZ51]

Jeff,

Do your parents live in the Bermuda Triangle?

[RussMcB]

Before I'd dive in to R&R the starter, I'd try rigging up something (perhaps temporarily) to provide 12v straight from the battery to the starter (perhaps via relay). The purple wire is fairly accessible and not hard to splice into. If the car always starts that way, you'll know the starter is not the problem (which is good. They are pretty deep to get to, and hard to find or expensive if you decide to buy a new one).

Hope this helps.

[Z51JEFF]

I think I'm going to bypass the switch first and then here very soon replace the starter. I've got a new starter in my stash and I've been wanting to pull the plenum to reapply a thin coat of heat sink grease to the backside of the spark unit so might change it at that time.

[XfireZ51]

I think I'm going to bypass the switch first and then here very soon replace the starter. I've got a new starter in my stash and I've been wanting to pull the plenum to reapply a thin coat of heat sink grease to the backside of the spark unit so might change it at that time.

If you're going to get the starter out, try a re-build kit. Inexpensive replacing contacts and cleaning off things. That's really all that's needed. $20 max.

[Paul Workman]

Paul,in one sentence you're telling me basically I'm wasting money replacing the starter and in the next you're telling me the starter is also troublesome,both of the no start issues I would like to address.Now here's where this thing gets completely bizarre. I've had this car for 8 years,I've put about 16,000 miles on the car in that time. Out of the 6 times the car wouldn't start 5 of those times the car was parked in the same spot at my parents house. Maybe I should park it across the street next I'm over there.

Well, I should clarify my statement a bit: A better way of putting it is to say that around (in my case and some others) the high-current contacts in the solenoid start failing around 40k miles (±). So, between the clutch switch and those contacts, they seem to crop up most often (but again around or after 40k miles...±)

But, hey! If you have a starter on hand (which you didn't initially mention), then go for it and refurbish the other so it will be on hand "if ever". Otherwise, the failure rates (observed) of the starter don't justify spending a couple hundred $$ or more when the known weak link is a $15 item...IMO.

As for the switch, others might not agree, but IMO the clutch switch by-pass is a no-brainer; an unnecessary precaution that should be moot to anybody that passed driver's ed...JMO, tho.

Sorry for the confusion. :o

[Z51JEFF]

Sorry for the confusion. :o

No confusion Paul,I'm at work right now and the confusion usually starts at the time I punch in😁. I really don't like the idea of by passing the switch but I'm just not in the mood to change the thing. When I finally found where it was I figured pulling the seat and the steering wheel might make the job easier but not today.

[Z51JEFF]

Jeff,

Do your parents live in the Bermuda Triangle?

A little bit of that and The Twilight Zone. After the 4th time I wouldn't park the car in the same spot,seriously.

[batchman]

I've been thinking I should relate the below story and this seems like the time. Here goes:

A Corvette driver recently pinned someone between his car and his trailer, with injury.
I did not talk with them, but gather that it "started in gear". Of course this can only happen if the subject switch is bypassed, or if a foot slips or a knee spasms etc. This driver has owned the car for several years, the trailer for maybe 2. Like any of us, this is someone you would expect to have good habits and situational awareness.

I too would probably bypass the switch if/when it happens to me, but the above gave me pause. Clearly, accidents can and do happen. A functioning clutch safety switch suddenly seems more important to my eye - and I would not have said that a month ago.

Seemed worth mentioning, back to your regularly scheduled program ;).

Stay safe out there,
- Jeff

[Dynomite]

Before I'd dive in to R&R the starter, I'd try rigging up something (perhaps temporarily) to provide 12v straight from the battery to the starter (perhaps via relay). The purple wire is fairly accessible and not hard to splice into. If the car always starts that way, you'll know the starter is not the problem (which is good. They are pretty deep to get to, and hard to find or expensive if you decide to buy a new one).

Hope this helps.

If you are going to cut the purple wire for diagnostics....After hot wiring your Solenoid to see that it functions, check the voltage on the hot side of the purple wire from the clutch switch with key on (Start) and clutch depressed. If you have 12v......just get the Relay and be done with it ;)

80 amp relay on Ebay (http://www.ebay.com/itm/60-80-AMP-RELAY-SPDT-SINGLE-POLE-DOUBLE-THROW-NEW-654-/110373059322?pt=LH_DefaultDomain_0&hash=item19b2bf3afa
)

Bypassing the Clutch Switch is NOT the answer :sign10:
Removing the Secondaries for a leaking Vacuum System is NOT the answer.
Blocking TB Coolant IS the answer. (These are all different questions) :D