mnmlod

Hi Guys,

I am at a loss for an issue I am having with my 91 c2. When the engine gets up to operating temperature and the ambient air is above 90, my car will not start after it is turned off. I have to wait until engine cools off somewhat. When I do try to start the car, it is completely dead...no buzzers, bells, dings, lights, whatever. I check the battery and it is at 14.3 volts. AAA put a load on it too and it was fine. If I just let it sit for 30 or 45 minutes, it cranks over and runs fine. I do not get this issue in the winter time. I have a feeling it's electrical, like some sort of voltage regulator or something. Any ideas would be welcome.

Thanks!

Mike

Spyerx

ignition switch?

mnmlod

I am not a mechanical type guy. Is the ignition switch actually located in the engine compartment or near the actual key? Is it, in itself, something that can generate heat and thus overheat?


Thanks!

Mike

cobalt

Sounds more like ground strap issue. Might want to bring it to someone if you aren't mechanically minded. Although you can remove the battery. Check to see if the terminals are cleaned and if so then just unbolt the ground strap which is right there. If it is not clean scrub it with some steel wool or Emory cloth if you have any and try again.

mnmlod

Thank you. I am making a list of things to try to fix or let someone knowledgeable fix.

I am curious how the ground strap would be affected by temperature though. Thoughts?

Mike

LouZ

As the temperature of a wire increases, its ability to transmit the "load", 12 volts, but high starting amps decreases. This is due by the exciting of the molecules within the wire by having them vibrate wildly, thus causing a higher resistance.

Assuming that the connection is loose, the load must pass thru a lesser amount of metal in the wire, think of a 4 lane highway dropping down to 1 lane, so when you have higher temps, you are actually decreasing the "amount" of wire that could carry the load. It only exaggerates the problem to the point where you can't get enough power to run anything

I tried to keep this simple, so I trust you understand what is likely happening.

Rocket Rob

If you are having trouble starting, I would measure the voltage at the starter when the engine is hot. Do you still have the same voltage as at the battery? If yes, then I would have your starter tested. If not, then you have a bad connection on either the positive or ground cables. You would need to start tracing the connections towards the battery to isolate the problem.

Edit: If you have zero power for anything, I would check your battery cables and ground straps. Remember there are two ground straps. One at the battery and the other at the starter.

cobalt

Process of elimination. The easiest thing to do is verify you have a complete circuit. I am interested in hearing what you find and if it makes a difference.

mnmlod

Thanks for the physics lesson. Sounds reasonable. I'll let you know what comes of it.

mnmlod

Oh, FYI, sorry for the late reply. It ended up being a bad cell in the battery. Replaced the battery, all is good.