mdixon

So there may have been some error on my part, after testing the relay I reinstalled it and checked the wiring on start and got 12v. Rehooked the wires up to the starter relay on the starter and it fired right up. Maybe when I checked the relay the other day I didn't install it correctly, but having a bad ecu I couldn't tell. All well, all better now

What relay does the start position energize? I was testing power in the top fuse panel and the ems relay 1 in the lower left corner, when checking the switch side to ground it energizes a relay in the clutch area. I wasn't sure if that was normal but I'm thinking it's not.

Cuz it does lol

Should it have 5v key on, not start?

Relay tests good 133 ohm, 86 has 20ohm resistance

So 85 has 5v with key on, 12v in start. Truck is 012413 Ecm vin is 012416

So this ecm may not work, I depinned 29 on the x2 connector, which is testing as starter relay ecm ground, and the ecm is supplying 3.5v with the key on to this circuit. I don't think I'm supposed to have voltage there.

Thank you

Pin 59 on the harness has resistance, 20ohms, other 2 grounds 0 ohms. Both 57,60 have battery voltage with key on

Which relay actually sends the 12v signal out to the starter relay?

This is key on, - on battery lug

Yes it does, f38 tests good, 12.5 on one leg no voltage on the other, in going to check the plug on the firewall now

Yeah, I've got constant 3.5v with key on on that red wire. I'll have to yank the doghouse to chase the wire any further.

So I think there's a short to power somewhere, key on the starting solenoid + wire has 3.5v on - battery post. Ecm connector + pin to the lug hoop has 0 ohms no other harness connections have any continuity to the hoop. Whatever took out the engine ecu seems to have also killed the abs module, because that's throwing a 254 code now that the ecm is on the can. The new ecm is from another truck that's basically exactly the same, ordered for fleet use with consecutive vin#s

So, I've got my data link back after swapping a good ecu. However I'm still not getting power to the starter when turning the key. Mid 144 Ppid 3 Fmi 3 I can't find anything on this code, I'm stumped.