Next step?

[Iyaoyas45]

Hate to say that I am asking on this site and less than 2 years ago I had all my training done and was and had been a certified GM technician for a while.  Ok. Here we go.  Helping I friend so for "customer complaint" I am going off there word.

2000 Chevy 2500. 6.0l

Driving down the road, went to turn on blower motor.  It was inop and battery light came on.  

 

Since I have been working on it:

Removed A/C-heater/fan motor control battery light still on

 

Tested voltage on both harnesses, no power except for alumnanation back ground light wire. 

 

Checked for codes, no codes (since I am no longer at GM, I only have a O'Reillys scanner)

 

Pulled off negative battery cable, hooked up test light clip to battery and the other end to the cable. ( I made sure all the doors were closed, waited to 15 minutes to put the computers to sleep.  It started at 10.3V.  If I pull the ATC fuse, Radio Fuse, and the TBC fuse then my test light will shut off, but if I put anyone of the 3 back in, I get voltage.

 

I guess I should have also said the charging system is working just fine.  Truck running 14.3V.

 

 

[CadillacLuke24]

Is the blower motor toast?

[riverbanks]

Try to get down to one fuse draw, disconnect connection at transfer case motor,and unfortunately radio connection,a back feed from anyone of these will keep bcm alive

[silveradosid]

unplug the wiper motor they are known for having a shorted diode that will back feed and turn on dash lights

[Jsdirt]

Check that 175A fuse and all the battery cables for corrosion. Sounds to me like there's a high resistance point (corrosion) that got REAL hot when the blower motor was turned on, and made the connection worse.