Chevy K1500 Electrical Issues

[dvanbramer88]

97 Chevy K1500

I received my PCM from pcmforless today. Got it hooked up, and when I went to start my truck, the battery seemed really weak and the starter wasn't doing much. I pulled up my dad's truck to jump it. After 10 minutes of being hooked up with jumper cables, it is hardly making a difference. I take his battery out of his truck and put it in mine, I get my trucked fired up. Put my battery in his truck to let it charge.

I got get gas, stop back at home to shut his truck off, and go for a ride. After 7 total miles, it feels like my trans is slipping, and 30 seconds later my engine shuts off, and I roll to a stop. I try to start the truck and the starter is doing very little again. Hardly turning for a second. My dad comes to give me a jump, and while I am trying to start my truck, he notices his amp gauge dropping to zero while I crank the motor. I can't get it started and he drags me home with a tow strap. Put the battery charger on the battery when we get home, battery charger shows a dead battery. Let it charge for a few hours, and it shows full battery again. I got to try to start my truck, and the starter again, just makes a little noise and barely moves. After turning the key just a couple times, the battery charger says the battery is completely dead again.


Seems like I have a terrible short in the starter or the starter circuit, and may possibly need an alternator too. I still don't know why the truck died while I was driving. Don't know if the battery got drained because of a bad alternator, or there was other issues going on. While the truck was running/driving it felt great right up until the trans felt like it was slipping and the motor died seconds after.

Any opinions?

[bartonmd]

Sounds like an alternator to me. It'll run fine off the battery until the battery gets low, then it'll run funny then die.

Are you showing that it's not charging when it's running?

Mike

[navigator]

I think Mike is right. I expect that your battery is reaching the end as well since it seemed your dad's battery didn't die as fast as yours. You might have it checked when you pick up your alternator.

[dvanbramer88]

Sounds like an alternator to me. It'll run fine off the battery until the battery gets low, then it'll run funny then die.

Are you showing that it's not charging when it's running?

Mike

I know that, and that is what I initially thought.


I haven't gotten it running since the motor died on the road. Got the truck home, and put the battery on the charger. Full battery a couple hours later, and after only a couple seconds of trying the starter, the battery charger shows that the battery is completely dead again.


That being said, I don't know for sure whether the truck died because of a dead battery, or the truck died for another reason, and the starter killed the battery trying to restart on the side of the road.


I may need both a starter and an alternator.

[dvanbramer88]

I think Mike is right. I expect that your battery is reaching the end as well since it seemed your dad's battery didn't die as fast as yours. You might have it checked when you pick up your alternator.

His battery is in my truck still. It is 2 years old. It was fine in his truck. After I got the truck home, we charged the battery with a charger. After a couple seconds of trying the starter (which was just making noise and trying to turn, not actually cranking) the battery charger shows that the battery is completely dead again.

[navigator]

you might be right on the starter as well. When they get weak they take a good bit more juice to turn over than when they are new.

How hard is your truck to crank normally? I would think about 3-4 cranks and it is running.

[dvanbramer88]

you might be right on the starter as well. When they get weak they take a good bit more juice to turn over than when they are new.

How hard is your truck to crank normally? I would think about 3-4 cranks and it is running.

Yea, if its cold, 3-4 cranks and its running. If the engine is warm, I hardly tap the key and she fires up.

[TBYODA]

Ok back up here. Your truck ran fine before you sent out your pcm for tune, right? You drove what 2-3 hours from school about a week before you sent it out. If the starter and alternator were on the way out and you were running on battery I'd think your truck would have quit running on the way home. Did you drive at all before you shipped it out? I'd take the alternator and starter to autozone to have them test them. I know they can do alternators IDK about starters. My gut says bad tune.

[bartonmd]

Ok back up here. Your truck ran fine before you sent out your pcm for tune, right? You drove what 2-3 hours from school about a week before you sent it out. If the starter and alternator were on the way out and you were running on battery I'd think your truck would have quit running on the way home. Did you drive at all before you shipped it out? I'd take the alternator and starter to autozone to have them test them. I know they can do alternators IDK about starters. My gut says bad tune.

My first thought as well, but the slow cranking from get get-go I think tells me something different. Also, I don't think the computer told the alternator how much to charge in those years, like it does on the TB, so just the computer not telling the alternator to charge wouldn't likely be it.

However, as I'm typing, I wonder if the timing in the computer is messed up, and it's firing the injectors/ignition well before TDC, which would cause it to not want to crank or to crank slowly?

Mike

[dvanbramer88]

However, as I'm typing, I wonder if the timing in the computer is messed up, and it's firing the injectors/ignition well before TDC, which would cause it to not want to crank or to crank slowly?

Mike

I charged the battery all night, it was fully charged this morning. I took the battery charger off before I went to work this morning. After work, i slapped a new starter in it. The old one was beat anyway, turns out, the gear/sprocket on it was stripped and the teeth were all bent up. The fly wheel looks ok. Anyway, the engine actually cranks now. But the battery was weak again. Threw the charger on it, and the charger said only 25% full. So maybe something was draining the battery all day. Letting it charge now. We'll see what happens when the battery is fully charged again. See how it cranks and if it feels like it wants to turn over. After that, PCMforless is getting an email. It may or may not be PCM related at this point.

[navigator]

did you get your alternator load tested?

[dvanbramer88]

Didn't get the alternator tested yet. And i don't see how that is relevant since the truck has hardly even cranked, let alone ran since it died going down the road on me.


Anyway, my update is, battery fully charged, still experiencing a no crank situation. Email has been sent to PCMforless.

[dvanbramer88]

Someone on another forum suggested to me that he really thinks it is the starter switch.

Based off the excessive draw, battery drain issue, and that it was apparently affecting other systems going down the road. And that a new battery and a new starter didn't change anything.

He said it was a common cause of electrical gremlins for my truck.

What say you?

[bartonmd]

I say that I went through chasing gremlins in my truck a few months ago, and I'd probably have been better off after the first obvious (cheap) thing didn't work, paying the $89 diag fee at the dealer. You know me, and know I'm not all about paying anybody to do anything but alignment and M&B tires, but...

Mike

[dvanbramer88]

I say that I went through chasing gremlins in my truck a few months ago, and I'd probably have been better off after the first obvious (cheap) thing didn't work, paying the $89 diag fee at the dealer. You know me, and know I'm not all about paying anybody to do anything but alignment and M&B tires, but...

Mike

http://troubleshootmyvehicle.com/gm/4.3 ... er-motor-1


I'm following this guide right now.

I just jumped out the starter, and it still has a no crank/very slow crank issue. Just clunks and hardly moved the engine an inch. That rules out the starter switch.

Next I am going to do a voltage drop test for the starter circuit.

I was thinking about paying to have it diagnosed, and than fixing it myself afterwards. I'm working a full time job now.

[bartonmd]

I say that I went through chasing gremlins in my truck a few months ago, and I'd probably have been better off after the first obvious (cheap) thing didn't work, paying the $89 diag fee at the dealer. You know me, and know I'm not all about paying anybody to do anything but alignment and M&B tires, but...

Mike

http://troubleshootmyvehicle.com/gm/4.3 ... er-motor-1


I'm following this guide right now.

I just jumped out the starter, and it still has a no crank/very slow crank issue. Just clunks and hardly moved the engine an inch. That rules out the starter switch.

Next I am going to do a voltage drop test for the starter circuit.

I was thinking about paying to have it diagnosed, and than fixing it myself afterwards. I'm working a full time job now.

Oh, definitely try and diagnose it yourself, but when it gets to throwing parts at it, it may just be cheaper to pay them $89 to tell you what's wrong, and do the repair yourself, depending on what parts can't be tested on the bench and have to be thrown at it, and how much they cost.

Mike

[dvanbramer88]

Well, I think my motor is toast actually....


I took the serp belt off, and everything on the accesory drive spins free, except, for the life of me, I can't turn the crank pulley. Even with a breaker bar and cheater pipe, feels like I am about to break the bolt off before the motor turns.

[bartonmd]

Did you try it with the plugs out?

It would make sense with what you're seeing, though...

[navigator]

oh man Dave, I hope not....
If it is it might be time for a TB!

If I know you though, you'll get one from a pick n pull and have it swapped in and back on the road in a few days.

[Wahugg]

Could it also be a failed or failing torque converter stuck in lock up?