I'M CONFESSING TO GOING TO COMPLEX TROUBLESHOOTING TOO QUICKLY. Don't do what I did.

(History) Finally got my truck on its maiden voyage after severe electrical gremlins and correcting previous owner's repairs. After 1.2 miles started losing power, overheating. Then, on the mad dash back to the garage, the dummy lights came on and engine wouldn't stay running.

(Bad repair process)(Don't do this first) since truck would start, then die after 3 seconds, I figured TPS, AFM, Ignition, COR relay or ECU. Removed and Checked all on meter and oscilloscope. No issues. Checked all continuity on associated harness wires. No issues.

(Repair) during last attempt to start, I noticed the alternator light was staying on and voltage never recovered. Got my megger and crawler and slid under truck to test alternator. Alternator/Waterpump belt broke. Yes, I did 7.5 hours of electrical troubleshooting before checking the belts.

 

i've done similar. it is what it is. you can at least feel confident in the parts you checked out and verified, eh?