title says it all. i put a wiring harness from a 2k truck into my 2k1 truck. i noticed that the alternator on the 2k wiring harness only has 1 wire going to it and my 2k1 harness had 2 wires going to the alternator. my dummy center light is flashing a picture of a big red battery and it's driving me nuts. can i turn this off with HP? or do i need to add a pin/wire to my harness to shut this thing up?

 

My 2000 truck with a 2002 OS has both p1637 and p1638 having SES enable unchecked and error mode 3-No Error Reported.

 

Stew i have the SAME exact problem, I am using my stock stock 2000 harness though, but when i did a PCM swap i got the Same battery light flashing and have been fighting it ( or used to it) for a year now.

All the error codes that deal with this are turned off in my tune, I cant figure it out.

I also swapped to a brand new Denali cluster and still have the problem.

I hope someone has a cure.

 

Just turn it off. it also throws that code if you upgrade the pcm to the older trucks.

 

I turned it off when I did the 02 OS upgrade.

There is a thread floating around where you can run a wire from the pcm to the alternator and it will fix the problem.

 

When I swapped in my 02 PCM (back before guys figured out how to tune this out), my blinking battery light wouldn't turn off until I not only ran the second wire from the alternator to the PCM, but I also had to install a newer style alternator (which you should already have obviously). I don't remember which terminal or connector that I had to tap into at the PCM, but I'm sure that info is floating around here. I know that both creederado and 99silver6.0 did the same repair and one of them posted up the info that I used myself. That wire has something to do with the PCM duty-cycling the alternator, and monitoring it's output IIRC.

 

It might but it might not. Running the wire didn't fix mine.

Under DTC processing enablers you need to set P1638 to not reported and under DTC MIL enablers you need to set P1638 to no MIL. I believe the first one disables the diagnostics for P1638 and the second takes care of the battery light. I also went so far to System > Vehicle Platform > Vehicle Platform Options and set Alternator F terminal to No. Between the three the light is off and stays off.

 

see below

bingo. worked for me i love it when a change goes my way. it doesnt seem to happen for me very often here lately lol

 

Coool , Ima try this and cross my fingers haha!

 

i have the same problem... ill try those codes this afternoon and see what happens