99 GMC 4WD Jimmy Starting Issues

ignition
gmc
batteries
starters
jimmy

#1

Starting one time in January, the SUV would have all ACC power but failed in every attempt to crank or turn. Nothing happened whatsoever when the key turned. No dim in the lights, the battery was fine. After about 30 minutes it started right up.

The issue started again this week, occurring twice. Both times while the vehicle had been sitting for more than 4 hours. I’m unsure what the issue is. I took it to Autozone to have them try and diagnose it to no avail.

I saw someone posted this same issue back in December of 2012, however the topic was closed before he had posted the final analysis and the user is no longer active.


#2

The next time the engine won’t start, place the transmission in neutral and then try starting the engine.

If the engine starts the problem is with the park/neutral safety switch on the transmission.

Tester


#3

I tried the neutral issue. It was the first thing I did. Apologies for not stating that.


#4

It sounds like that other GMC Jimmy you mentioned probably had a bad starter. It’s easy to check if power is reaching the starter solenoid when the engine won’t crank. If there’s power at the solenoid but no cranking, the starter is the problem.


#5

Okay.

Remove both battery cables from the battery.

On the positive cable peel back the red cover to expose the battery terminals. If a lot of corrosion is found under the red cover on the terminals replace the positive battery cable assembly.

Tester


#6

Jesmed, that was the user I was referring to. When the thing does start, it starts with no stall or anything. Could it really be the starter?

Tester, will try that and get back to you.

Thanks for the help, guys.


#7

Starters can easily be intermittent. Normally you would get a click out of the solenoid, but anything the solenoid does can also be intermittent. Battery cable or terminal corrosion can also oddly intermittent.

What jesmed was saying is that it’s really easy to cut the search in half. When you turn the key as 12V signal is supposed to be sent to the starter to tell it to energize. The starter has a big fat wire that is connected straight to the battery and provides the juice for actually turning the engine over to get it going. And it also has a little tiny wire (the “S wire”) which is what activates to solenoid - and that is just a really heavy duty switch for the starter motor. If the S wire doesn’t get 12V, then you know to go backward in the start circuit (e.g. starter relay, neutral safety switch, ignition swtich). If the S wire DOES get the 12V then the problem is PROBABLY the starter.

Anyway, it’s just a very simple diagnostic place to begin. So too is just cleaning and inspecting the cables & terminals.


#8

Excellent comments above. Just to clarify, even when things are working correctly the S terminal usually won’t have 12 volts during cranking. That’s b/c the amount of current to crank the engine is enough it drops the battery voltage. But if you have 10.5 volts or higher on the S terminal during attempted cranking and it doesn’t crank that makes the starter the prime suspect. When making that measurement it is important to measure between the S terminal and the starter case, not the chassis or the battery ground.


#9

I’ll have to wait until daylight to do most of this. Something I failed to mention, I have a remote starter that was installed when I bought the truck.


#10

Does it start w/the remote starter when it won’t start with the key? Or is it equally inconsistent w/the remote starter?


#11

An intermittent problem relating to the starter is most likely. Of course bad battery connections, and loose wires at the starter could also be possible.

I have seen aftermarket alarm systems cause intermittent starting problems as well.