Weird truck electrical issue

[710ltd2002]

Lots of great responses on tracking wiring problems. I think I would put a new STARTER motor in it first. Your symptoms sound like what I had with two Silverados. Both only needed a starter. I tried lots of other things with the first one before getting to that. . . . . Dave

 

[Brownie450]

If you have a "hold against" Ammeter, try reading current draw
when this problem comes up. If no current draw on the large
battery cable with 12 plus Volts at the battery, look for a bad
connection or ground.
Jim

 

[wore out]

If you have a "hold against" Ammeter, try reading current draw
when this problem comes up. If no current draw on the large
battery cable with 12 plus Volts at the battery, look for a bad
connection or ground.
Jim

It would have been nice if the O.P. would have posted the resolution to this over a year ago!

 

[used red MN]

If you have a "hold against" Ammeter, try reading current draw
when this problem comes up. If no current draw on the large
battery cable with 12 plus Volts at the battery, look for a bad
connection or ground.
Jim

Yep wo, in the middle of typing out.. another one falls victim to “Old-post-uritous” good info added though. Will see if the OP chimes in to let us know if he figured out a cause.