Soooo long story but here goes. Truck was t boned a few years ago but has been repaired and ran pretty regularly for about 2 years. I lost the key had locksmith come and made a new one. It started and ran 2xs then nothing. Acted like dead battery so he threw it on the charger and I went back to my truck. Hasn't started for 7 months. Not sure if i remember everything he has done but here goes. First he replaced starter and a sensor for the shifter. Power but still nothing, but he could jump and spin the starter but trip the anti theft. Got in it the other day and the anti theft light was blinking like crazy for code for the transceiver. Replaced that. Then nothing again. Click but not even try to turn over. so he started moving relays around and it started. Starter rely was replaced. Started and ran just fine 4 or 5 times ran 15 min then off and back on 4 or 5 more times. It had the wrong battery in it and hood wouldn't close. So I swapped battery's and back to acting like the battery was dead. (Took it streight out of the truck I was driving it was fine) he jumped the started and it tripped the anti theft waited 2hrs and back to acting like a dead battery. He swapped the starter relys again nothing. Out of pure frustration i turned the key over 4 or 5 times in a row then there was no power in cab. No dash light, head lights nothing. Theft light is very slowly blinking. Only power it has. I replaced the rely for the cab fuse box #1 under the hood thinking it might have blown something there and the pcm rely becuase he couldnt get anything to come up on the tester in any of the holes for that relay. And checked every single fuse in the truck everything is fine and has power at the fuse box and no blown fuses. I'm ready to push it off a cliff. What have we missed? Is it the actual PCM? How do we test that? I am so done dumping money in it but it's a good truck.

 

Going out on a limb here, but have you looked into the ignition switch?

 

There was power in the gages before the recent complete loss of power. The key turns over and the theft light blinks when it's in start postion. I would think it wouldn't do anything if it didn't have power. But I will have him test the power on the column. Thank you!!

 

The next thing to look into would be the grounds. You're not just looking for broken wires, you're also looking for corrosion in both the terminals and the actual wire itself.