Stranded on a road trip, '90 ZR-1, no crank

[Dynomite]

These type of issues that are often electrical and intermittent on a 30 year old car can be fixed but often the solution is not specifically identified. The solution takes a lot of patience and often is trial and error (mostly error)

I have run into a couple examples .......one a water pump impeller spinning on the shaft (mechanical) and another as follows which was electrical.......

Post 244 - INJ1 Fuse Keeps Blowing

One solution I never tried was to remove the fuse in line and see what smokes....But that could be costly

I actually picked up the 95' ZR1 500 miles away and it functioned fine all the way to my garage.......then a few weeks later the INJ1 fuse issue started 1/2 mile down the road from my garage

Keep us posted in this thread and sooner or later one of us will offer the fix among many fixes offered and in the end we will not know exactly what the real fix was or how long the fix will last

I have one of those electrical issues taking place on a 90' ZR1 now involving the tachometer quitting intermittently.....nothing else on the ZR1 is negatively affected or inffected........

[Tim555]

I am also experiencing an intermittent no-crank when hot issue. I want to rule out the clutch safety switch. When I have the issue and I push the clutch in and turn the key to start I get a voltage drop. If I do not have the clutch in and I turn the key to start I get a slight voltage increase. Am I correct to conclude that the clutch switch is working because the voltage drop when the clutch is in is due to current being sent to the starter, and the voltage rise when the clutch is not in is due to the accessories being turned off, but no current going to the starter?

[ZBrink]

Originally Posted by Raykahn

This sounds similar to what I was just dealing with in my 90. When cold it would start with no issues. Once the engine was warm it couldn't start without a push. Replacing the starter fixed it.

Cutting out while driving is strange. I did not have that. I don't think that would relate to the starter, so you may have 2 different issues. Maybe a grounding issue? The other other WAZOO Zack (god, there's three of us now) had electrical/grounding issues with his Z. He might be able to speak to some of the symptoms he saw.

For mine, cold or warm makes no difference as to when it will or will not start. It also tuns off randomly so I believe I can eliminate the starter as an issue. I believe the two issues are related.

[ZBrink]

UPDATE: I had the car running in the garage while trying to tuck back some wires I had dangling still from pulling the HVAC Program Module. When moving around the wires, the car abruptly "turned off" just as it was doing while driving. So, I turned upside down and looked up around the wiring and saw this sorta "frayed" wire in the photo. Obviously I need to repair this wire but does anyone know off-hand what it powers/controls? I'm very admittedly not good with electrical but will try and look through the Electrical Supplement to the 1990 Service Manual.

Also, does "at'ing" people work in here like it does on the CorvetteForum? @Mikey

[Mikey]

@-ing does not seem to do anything on this forum. I pretty much check it daily anyway so if you are trying to reach me it is not too hard lol Corvette form on the other hand I do not frequent nearly as much.

I cannot really tell from your photo where that set of wires is at. Also difficult to determine if that is part of the original harness that has a splice in it or if those wires are part of some sort of aftermarket, radio or other accessory install. Brown wire is typically a positive power feed wire on the accessory side of the ignition.

Good to know that you may have found a way to replicate the issue you were having. That harness repair should be relatively easy.

[dredgeguy]

Looks like step one to narrow down the cause has been more or less determined. If that is it will be an easy fix.

[ZBrink]

Originally Posted by Mikey

@-ing does not seem to do anything on this forum. I pretty much check it daily anyway so if you are trying to reach me it is not too hard lol Corvette form on the other hand I do not frequent nearly as much.

I cannot really tell from your photo where that set of wires is at. Also difficult to determine if that is part of the original harness that has a splice in it or if those wires are part of some sort of aftermarket, radio or other accessory install. Brown wire is typically a positive power feed wire on the accessory side of the ignition.

Good to know that you may have found a way to replicate the issue you were having. That harness repair should be relatively easy.

Thanks for the quick reply Mike. I wanted to post an update vs contacting you directly so that everyone who was helping and interested was tracking. But, I was definitely hoping your electrical engineering skills would step in :-) That wiring harness appears factory and is underneath the steering column. I'll edit tonight or tomorrow with an additional photo to better display the location. I may need help making heads/tails of the wiring supplement.

[tiegsd]

Had same issue, similar symptoms. Ended up bypassing the clutch safety sw under the drivers hush panel, no issues since. That said, yours sounds a little more complicated. If i recall, the switch wiring goes to a relay, which picks up when the safety sw is actuated. Part of the starting circuit. Intermittent shutdowns sounds like a different issue.

[Tim555]

Originally Posted by Tim555

I am also experiencing an intermittent no-crank when hot issue. I want to rule out the clutch safety switch. When I have the issue and I push the clutch in and turn the key to start I get a voltage drop. If I do not have the clutch in and I turn the key to start I get a slight voltage increase. Am I correct to conclude that the clutch switch is working because the voltage drop when the clutch is in is due to current being sent to the starter, and the voltage rise when the clutch is not in is due to the accessories being turned off, but no current going to the starter?

Shop that sold me the car replaced the starter and it still has the no crank issue when it?s hot. I also noticed the voltage gauge dropping when the turn signal is on. Could it be a bad ground somewhere that only manifests itself when hot?

[mlipmd]

Are your battery connections clean and tight? What is the battery voltage?