Heater gone -5 degrees CODE RED!!

[mistaken1]

Necro post. I too am having a similar problem. My blower motor wasnt working, so I pulled it thinking it was bad, I bench tested it and it was fine. So I put it back in and used a jumper wire to verify it had a good ground, it spun just fine.
Now heres the part that is giving me fits. With the key on and fan switched to high, I am getting 12volts at the motor plug under the hood, but with a load (a test light) the voltage dropped to nothing. To test this I used a test light and meter in parallel, unhook the light and the voltage shot up to 12+.

Any ideas what may be happening? I am at a total loss here.
-Jesse

Bad/corroded connection in that circuit. When you put a load on the circuit all of the voltage drop takes place at the high resistance joint.

 

[JWNathan]

Okay, wiring all looks good, no melted plugs either. Is there a way to check the resistor to verify if its bad? Thanks for the help so far guys!
-Jesse

 

[ssgtwright-usmc]

Remembered an older post here when someone mentioned that the GEN1/alternator and the heater switch are connected within the same circuit series.
Its something about some resister to excite something and thats why the GEN1 light gets brighter when you turn on the heater full speed.
So I dont know if this will cause a problem with your fan not working but its just a idea of something to look at within the wiring system.
Other than that, you just might have a bad fan motor.

 

[JWNathan]

Got it to work. Was corrosion on the switch that was the problem. Works great now, thanks for the help guys!
-Jesse

 

[Seabee15]

I just had this very same problem. the switch was loose and corrosion was present.

 

[kassim503]

+1 on the heater switch problem, take good care of the connector, if its been going bad for too long it will melt the switch housing

That 12v with no load and 0 with is a tricky one isnt it?