Help me fix her, please!

jzuelly

Okay, so I have a 1996 GMC Jimmy a couple of weeks ago I had what I thought was a starter issue. It turned out that the ignition fried and burnt up the starter. Those were repaired. Put her back on the road immediately sporadic starting issues. Took her back to mechanic he said he looked couldn't find anything told me to take her home. I tried to start at shop, wouldn't went back and ask him if he could show me how to start my own truck? He couldn't, left her there turned out relay on fire wall burnt up as well. Took her home back to some time she starts and sometimes she doesn't. I'm female and haven't any mechanical background. I do have power, the dash lights up but no crank, no noise. Any ideas would be greatly appreciated.

Mr_Shiftright

No way to diagnose this remotely. When the failure occurs, someone has to be there to find out what went missing. You start at the starter solenoid with a probe and work backwards. Your mechanic, at least from your report, sounds like he could care less, so maybe you need to go to someone with more skill at this sort of thing, rather than a parts replacer.

jzuelly

Thanks.

thecardoc3

Does your Jimmy have a manual or automatic transmission? If it is an automatic, have you tried shifting this to neutral when it acts up and see if it will start? When it doesn't start have you tried shifting back and forth between neutral and park a few times and then re-tried?

Do you know how to use a voltmeter or a test light? Do you have either a voltmeter or test light? If not now would be a time to buy at least a test light. Here is a little video on how to use one.
https://www.youtube.com/watch?v=ksrsXwwukFc

There is a 10 amp fuse, socket #20, in the instrument panel fuse block. Get your owners manual and it will show you the exact location. It should have power (on both sides) when the key is turned to the crank position only.

If you have an automatic then the following checks would help identify the area of the trouble, a manual is slightly different.

The relay that you mentioned on the firewall, it should have a yellow wire going to it. There should be power at that yellow wire when the key is turned to the crank position too. Fuse #20 is in-between the ignition switch and the neutral safety switch on the transmission and the relay is after the neutral safety switch and controls the power to the starter. If you had power at fuse #20 when the key is in the crank position but not at the yellow wire for the relay then there is a problem with the neutral safety switch or the wiring in-between those points.

There are two black wires at the relay, one of them has power all of the time the other is grounded. There is a purple wire at the relay, it is the wire that connects to the starter solenoid. Using a test light, and jumping from the black wire that has power to the purple wire it should light up.

If you use a piece of wire and jump power from the black wire to the yellow one, the engine should crank with the relay in place. Jumping power from the black wire to the purple should directly cause the starter to crank the engine.

Depending on what is found with these checks, the next step in the diagnostics can be chosen.

jzuelly

@thecardoc3, It's an automatic. I took it back to the mechanic or parts replacer as mrshiftright referred. The only thing I had done to get her to start was touch battery cables to see if they were loose but they are not, that had been making her start but not anymore, shifting the battery I thought had something to do with it.She is old I know that but I carry mail with her and there is nothing that can carry the load she does. This first started by, I thought, the starter hanging up. Tapped on the starter to see if she would start to take her to mechanic as not to pay tow, not! She started smoking couldn't get hood to open went running for fire extinguisher. Hood finally released no fire but an awful smell. Mechanic replaced starter was in bad shape but she still wouldn't start. He said that the ignition had messed up and sent power to starter burned it up which is what my neighbor had said happened to his wife in their auto. Went to work in her had a terrible gas fume in car all day carrying mail. Then the sporadic start as stated, mechanic said he looked at her all day, started every time for him, but when i went to take her home she wouldn't start then he discovered that relay was burnt up he did not charge me for the labor just the part.I assume it's difficult to diagnosis if it's not behaving that way for him. He thinks it's in the wiring from when she was smoking. He told me this morning, if she wouldn't start to bring her in, to wiggle the wires at the relay he replaced, but she started go figure. I thank you for your info and when I get her back and she starts this again I will apply and get back with you then. We are going into the heavy season on mail and my PT just isn't built for this kind of work. Bless you and have a wonderful day.