packratt
Active Member
Looks like the computer is telling you what else is wrong. Make sure the glow plug system is also working. I would remove a glow plug, put in a pair of grounded vice grips, leave the engine harness plug on it and cycle the glow plugs with the ignition switch. Does it glow? Verify at least you got 12v on both banks with the glow plug (or WTS) light is on. If the glow plug system is working verify the ECM is getting a signal from the glow plug harness when the plugs are "on". Perhaps swap ECM's with the test truck.
As I posted a week ago, glows were tested. All glows were pulled and voltage applied. A couple were tested using the ignition key and factory glow plug wire by removing, grounding and turning key on. All glow plugs are working.
After getting the glow plug relay and brake switch codes the codes were cleared and currently have no codes after additional starting attempts.
Block heater work? I have had luck in Colorado winter weather to get a 6.2 started without glows just on the block heater.
When I have to start plugging the truck in when it is 50-60 outside, I'll quit doing anything with diesels. That being said, I did try plugging in a couple weeks ago when it was cold. Didn't make any difference. I didn't hear any of the typical block heater sizzle but I didn't check resistance through the heater.
Without looking at a schematic is there anything related to the brake switch and glow plug relay? Still acts like a rub through short somewhere.
I'll check but I can't think of any reason why either would disable start.