hey guys...
replaced 2 bad GPs on thursday...havent drove very much, but this morning it was like 30 degrees and the truck was hard to start(harder to start then with 2 bad GPs). then after dropping off my daughter at day care, the LED for the GPR didnt come on. will the gpr not come on if the truck is warm? has my GPR took a S**t...i already checked the voltage before replacing the GPs...so i know it WAS good. is it common for them to go out after a GP change?

Just to note...after sitting for about 1 hour, the GPR LED does come on now...

also can i use the relay for the AIH? if so how can i make sure it is working...
thanks for the help...
chris

 

It's normal for the GPR not to come on when the engine is hot. And yes, you can try the AIH relay in place of the GPR. You need to measure the voltage *drop* between the input & output (large) terminals when it's activated. Anything more than 1 or 2V or so is too much. Lets say the GPs pull 100A -- a 1V drop at the relay will dissipate 100W at that point. Think how hot a 100W light bulb gets. Much more of a drop at the relay and you'll be melting the little boot that covers the input terminal.

 

The AIH delete relay can be used for the GP's. The PCM uses a lot of parameters in order to determine the need for the GP's to be energized. It includes ambient air temp, oil temp etc. when making the determination. I have seen mine come on on 70 degree days for longer than a minute when my truck has been sitting for as few as 3 hours. I have seen mine not come on on 35 degree days when it has been sitting for 1-2 hours. It's kind of funny like that.

 

Damn Joe, you must have submitted that right after I clicked on to read the thread.

 

thanks guys...ill check the voltage drop at lunch. do i check the AIH relay voltage drop the same way?

 

ok...checked GPR...11.8 coming into it, 11.59 coming out...wehy would it be harder to start??