Need help, electrical, won't crank

[d_dowler06]

OK, truck drove fine yesterday, today won't start. I have a 1983 gmc k2500 with a 6.2 j code. Turn the key to crank and sometimes get a click, sometimes nothing. The big hints its throwing at me... Sometimes everything turns on with the key in the run position and sometimes nothing happens. Lots of times I turn the headlights on and they don't come on for a while. Sometimes right away sometimes 30 seconds later. Makes no sense to me. At first I thought ignition switch but then noticed the headlights and don't know where to look now. Anyone have similar issues or know where to look to fix my problem?

 

[Georgeb]

A few first checks...
-battery is good.
-battery connections clean and tight.
-grounds clean and tight.
-when it's acting up what circuits have or don't have power at the fuse block?
-The harness connector to the back of the fuse panel connected properly.
-any drain on the battery with everything off.

 

[350runner]

sounds like the classic "looks good" positive battery to starter cable.

Sent from the dust in front of you!

 

[d_dowler06]

Well I ended up hooking the battery back up Tuesday and it started right up. Didn't drive it or anything because there was other things I was wanting to do anyway like an oil change and stuff, realized I needed it tomorrow morning so I got everything cleaned up and wouldn't you know, same problem again. The one battery is a cheap rural king one that is 3 years old so I am rolling the dice and hoping it was a bad battery. I went and bought a new battery at Walmart tonight and put it on and the stupid thing still won't start. I put it on the charger at 40 amps for 5 minutes or so and voila, it starts right up. I am going to be driving it an hour away tomorrow so I hope it decides it is ready to run and not be a pain in the ars.

 

[PrairieDrifter]

yeah it sounds like a typical battery connection issue if it still gives you issues I would buy new battery cables and new terminals all around and make sure your batteries are the same.

 

[d_dowler06]

Well this morning truck wouldn't start so I put it on the charger again with 40 amps and let it sit for a minute or two and it fired right up. Drove an hour away for work, then come out and truck won't start. Put jumper cables on it and no different. Long story short an hour later of tinkering in the mud and rain and 40 mph winds I tapped on the solenoid while a guy cranked it and it fired up. Just got out to the shop and was going to take the started and solenoid off and I noticed the positive going to the solenoid was only on hand tight. Really hoping that's the issue. Will go out tomorrow and put the batteries back in and see if she'll cooperate. I really appreciate everyone's help. This is a great forum.

 

[89Suburban]

Looks like you found the problem.

 

[d_dowler06]

That was the problem! Truck runs great. Now to find why I'm not getting power to the blower motor. I have power going into the cutoff relay but not coming out. Tested all the wires, red one going in has power but nothing else does. I replaced the relay but that didn't change anything. So I am guessing the signal wires aren't delivering anything?

 

[chengny]

I would guess the blower resistor stack is NFG or maybe your motor ground cable is disconnected or broken:

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A smoked resistor set is probably the most common cause of loss of blower speeds. And since you have A/C (and your blower housing is plastic), the motor must have an external ground. That cable must be intact and it runs to the firewall where it needs to have a tight clean connection.

 

[highdesertrange]

just a hint here, I know you found your problem. but on diesels with 2 batteries you are suppose to treat them like one battery. in fact whenever you have batteries in parallel you should treat them as one battery. they should be of the same age and rating. any type of mismatch of age or rating will give you shorter battery life for both batteries. highdesertranger