I lost the alternator on my 99 today and the bad one was still under warranty. Got a reman one from Kragen and installed it but it still does not charge!! Is there something I am missing here?? Is there anyway to check the PCM and see if it is that? I am gong to pull the new one off and have it checked tomorow, but what are the odds that a new alt. is bad?

I also checked the bus fuses under the hood and the 140 was good along with all the other fuses in the box. No codes visible either

I am really stumped on this one, never had a bad alternator not get fixed when I replaced it

Chris

 

Check that the 12v line from the harness (small gauge wire) that excites the field is hot. If it isn't your alternator won't charge.

 

is that the small double plug??

Chris

 

OK, Checked the exciter plug with the truck turned on and not running and got .2 volts. Checked it with the motor started and got the same. Looks like I am not getting voltage from the PCM. researching it looks like maybe the crank or cam shaft sensors will cause this issue. Which one do I change, and where are they????

I am really at a loss for this one, and it is getting DARN COLD to be riding the motorcycle to work!!!


Chris

 

only codes were a P0252, now what???


Chris

 

Chris,
I don't have a wiring diagram to look at but I some how doubt it is a crank or cam sensor issue, the truck probably would not run if it was.
I would be more inclined to think that you have a partial short circuit to ground that is pulling down the voltage on that line, the fact that you have .2 volts means that the continuity to ground is not strong enough to blow the fuse. Follow the harness back from the alternator plug and look for any wear from rubbing due to vibration.

 

i will go back and check the wires tomorow. I am also going to double check the grounds just for kicks.
Thanks mikelr
ANY ONE ELSE PLEASE!!!


Chris

 

OK, i have been through everything I can find. The wire check out from the alt to the pcm fine, all grounds look good and I don't see anything else.

One thing I did notice was the battery temp sensor is giving kinda wierd ohm readings. Could this cause it to not charge?? Can I leave this unhooked??


Chris

 

i am going through the same thing only my tach is not working.
All this was after I fixed some KDP damage so i was thinking it would be the crank sen., and i just got the dampner on wrong, but thats not it.
I was wondering what supply voltage to the crank sensor should be.

 

I ended up puting an external voltage regulator on mine because the PCM is shot. I put 12 volts to the alt. to test it and the voltage started going up quick and I pulled the line voltage.

Sounds like your issue is a bad cam or crank sensor. That is what causes the loss of tach

Chris