Ever hook jumper cables up backwards?
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Tuned
Joined: Mar 2006
Posts: 455
Likes: 0
From: Luxemburg WI
All fuses and relays check out. Alternator diodes are not draining the battery. Ran new power and ground wires and no change. Still won't crank. Did notice that when you release the ignition after trying to crank the dash cluster goes into a twitch fit. Makes a rediculous clicking noise and all the gauges and lights jump and flash. Not sure if it normally did that but my nephew didn't remember it before. I plan to pull the alternator and starter and have both checked. Both new but that doesn't mean good. Below zero right now and the truck is outside so waiting for a break in the weather for now.
Fleet Mechanic
Joined: Jul 2017
Posts: 1,448
Likes: 163
From: East Texas
I had an Oldsmobile that kinda did something similar with the gauges. They would do a full sweep then hiccup a couple of times and then go dead. Dash lights too. While going down the road. Dealer never could get it to occur while they had it. Turned out to be one of the battery posts inside the battery was broken. When we hit a bump just right it would kill the electrical. Didn't find it until we replaced the battery because the battery was located under the rear seat.
Long story I know, but check to see that both battery posts are solid.
Long story I know, but check to see that both battery posts are solid.
Cargo Master
Joined: Jul 2009
Posts: 2,541
Likes: 54
From: Des Moines
If I’m repeating anything already mentioned, I apologize, but I did try to read through the thread completely.
You said in your initial post that the truck ran for a day or so after the jump and then quit - that’s a pretty strong indicator that the starter circuit and related components/wiring were fine and I think at this point, you need to be looking at what the PCM is doing.
Try pulling codes and see if there’s anything useful - anything relating to power supply or memory codes would be the focus.
You can also pull the starter relay and jump pins 30 & 87 (key doesn’t have to be on) - if the engine cranks, and you’re certain the starter relay is good, then for some reason the PCM isn’t grounding the relay or there’s a power supply problem on the coil side of the relay.
You said in your initial post that the truck ran for a day or so after the jump and then quit - that’s a pretty strong indicator that the starter circuit and related components/wiring were fine and I think at this point, you need to be looking at what the PCM is doing.
Try pulling codes and see if there’s anything useful - anything relating to power supply or memory codes would be the focus.
You can also pull the starter relay and jump pins 30 & 87 (key doesn’t have to be on) - if the engine cranks, and you’re certain the starter relay is good, then for some reason the PCM isn’t grounding the relay or there’s a power supply problem on the coil side of the relay.
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