gt0987

So yesterday after getting gas I hop in the truck to head home. As I turned the key I heard a pop and then nothing. When I say nothing I mean there’s not even interior lights. I suspected a main fuse so I checked all the fuses in the engine bay fuse box, they’re all ok. I checked all the fuses in the interior fuse box and they’re all ok. I call a friend and he come out and has a meter so we see the battery is showing 12.8 volts and that the main fuse box is getting power.

Without much else to do we try jump starting, which I’m thinking is a waste of time. But, with the cables hooked up I get in and the interior lights are working, ok that’s good. I turn the key and my engine slowly, and just barely, turns but does start. I disconnect the jumper cables and I’m surprised that it keeps running, and drive home, about a mile. It drives ok but there was an alternator sounding whine as I put the windows up (power windows).

Before I shut it off I looked at the gauges. The charging gauge shows 18V and drops substantially when I hit the power window button and the whine returns. I shut it off and again there are no interior lights or anything. I have an extra battery so I swapped that in and still no power.

I know there’s a circuit not being completed somewhere. Maybe a bad alternator? If it’s a bad ground then where should I look to find the ground wires? If the grounding is bad I would expect it not to run at all so the jump starting confuses me. Is that normal? (Is it normal for the truck to run, it is certainly normal for me to be confused)

I’m not good with this type diagnosis so please offer advice if you have any.

Thanks.

Bobzombie

Did you connect the jumpers to the batt terminals?
If you did then its not a ground wire issue.
How long does the truck run once started and if you shut it off it will not start back up??
I would check voltage while running at the alt and have some one apply a load (i.e. blower motor) and see if it drops. if so the it would be the ALT Also while running at idle you should have about 14v at the battery if the alt is charging.
also I have a good used alt if you end up needing one.

TNRabbit

Check this one under the hood:

gt0987

I did connect the jumper cables to the battery terminals. If that indicates no issues with the ground wires then I'm a happy camper. I only drove about a mile from the station to my house but the truck ran fine for that mile and was idling fine in my driveway. When I shut it off I tried to restart it immediately and there was no power, not even interior lights.

After getting home, but before shutting the engine off, I watched the charging needle on the dash and it dropped a lot when I used the power windows. I didn't check the voltage at the battery then. Should the voltage across the battery terminals also be about 14V while the engine is running?

The fuses in the engine bay were the first things I checked and none of them are blown.

Thanks a lot for the help.

gt0987

I feel like a bozo. It turned out to be a loose connection at the battery terminal. I had to replace the terminals a while back and the connector bolts had worked loose. I heard it arc when I was hooking the battery back up so I checked them then and found the problem.

Thanks for the help.