My wife’s 2001 GMC Jimmy Diamond Edition has almost 200,000 miles on it. We’re trying to figure out why it has a starting problem. We know that it is not the battery or charging system. She has full electrical power when she inserts either of the two car keys but when we turn the key we get nothing. No clicking, nothing at all. I can hear what sounds like a relay under the dash clicking but nothing under the hood. The first thing in the morning it will start. Then later in the day it won’t start at all. The frequency of it not starting has been increasing over the past several months to several times a day now. We have found that opening and closing all the doors, opening and closing the rear hatch, locking and unlocking the steering wheel, tilting the steering column up and down, shifting into neutral and into park, taking the key out and putting it back in, locking and unlocking the doors with both the key FOB as well as the electric door switch and waiting anywhere from 5 to 45 minutes will solve the starting issue for that one time. It always seems to be a different thing that we do last before the jimmy decides to start. When it does decide to start it does right away when you crank the key. We don’t see the Security light flashing or lighting steady on the instrument cluster. The starter is the original starter so I don’t know if the starter could be the problem or whether the security system is having issues with the keys. We have it in at our local mechanic and we’re hoping it won’t start for him so he can try to figure out what is causing the jimmy to refuse to start when you turn the key. Has anyone ever run into something this crazy before? If so, how did you diagnose the cause in order to fix the problem?
Have you tried starting the engine with the transmission in neutral? If not try that. If the engine starts there’s a problem with the park/neutral safety switch.
If the engine still won’t start, then remove both side mount battery cables from the battery. On the positive cable peel back the red cover to expose the positive battery terminals. If you find a lot of corrosion under the red cover on the terminals, replace the positive battery cable assembly.
My first 2 thoughts are a bad ground or starter motor connection. Check and clean the ground at the engine block, and the positive stud on the starter motor. It may even be a bad starter motor. My second thought is the ignition switch or shift interlock is failing. I like to play whack a mole kind of game, with a rubber mallet. Start with the starter motor, see if it makes a difference, then try the steering column, see if it makes a difference, or be able to replicate failure mode for analysis.
It is a small list but the prior posts say most of the issues a high mileage car could have. I personally like @Barkydog key switch issue, but the neutral/ park safety switch is another quick check.
The battery, battery connections, starter selenoid, the starter itself, the xmission/clutch safety switch, the starter relay, battery, wiring, and ground connections are all a possibility.
When I have this problem the first thing I do – after verifying that the battery connections are clean and not corroded – is to determine if the starter is the problem or not. A mechanic can measure the voltage on the two starter terminals. Both should be 10 volts or more during cranking. If either is significantly less than 10 volts, certainly if either is below 9.5 volts, then the problem is most likely not the starter. If both are above 10 volts, certainly if above 10.5 volts, then the starter or starter selenoid is most likely faulty, or there is something preventing the engine from turning.
I assume the warning lights don’t turn on when the trouble happens and if so then I would have to think either the power connection to the ignition switch has a problem or the switch itself is bad. I suspect it is the switch that is bad.
Thanks everyone for the suggestions. I’ll run these past my mechanic. Placing the truck in neutral and then trying to start does not work. It always seems to be a different fix each time to get it to start so it’s either a coincidence that I’ve messed around for 10 minutes or it’s always a different problem (which doesn’t seem likely).
I picked up the Jimmy from my mechanic today. It wouldn’t start for him and he believes the problem was the original starter motor 199,000 miles on it. He mentioned that the radiator leak he had repaired recently may have been dripping on the starter and cause it to corrode. Apparently there’s not a lot of room to remove it and it required loosening a motor mount to tilt the engine to get the starter out and the new one in. I’ll update this next week to report back on whether the starter was indeed the culprit for this intermittent turned almost always starting problem. Thanks for everyone’s suggestions, by the way.
If the trouble was occurring while the mechanic had it for testing then there should have been no guessing if the starter was the problem. That is very easy to determine by checking the voltage to the solenoid.
I understand this discussion is forever ago, but we just resolved our issue. Sometimes the car would start. Putting in neutral did not fix it. New battery, so that wasn’t it. If you turned the ignition key, nothing. It wasn’t related to cold, warmed up, etc. If you held the key to on, eventually the car started. Sometimes it would be 30 seconds, then boom it started fine. We replaced the starter. It is very cramped. Zero access from above. Had to tilt starter up to access battery and ignition wires. No special tools, just long socket for the battery cable nut. Getting starter out just took some turning, twisting and eventually the right direction got it to pull out without moving motor mounts, frame bars, etc. Cables are keyed with a tab, but note direction of battery cable, it can go two directions. I left existing shim, didn’t add any new ones. Works great now.
It’s unusual for a starter to fail in a way it doesn’t even click @DIYmoosetips , but you’ve proved even that is possible sometimes. Thanks for the tip. Good job at replacing the starter – isn’t that a fun job when you are laying under jack-standed car in your driveway? lol — and best of luck. I think you are due extra duty pay!