Resistor failed.

 

Resistor has nothing to do with high speed..
@Hummerz can you please repost the sequence in checking/swapping the UH fuses/relays??

orange wire should be batt v and comes directly from UHFB

 

@bassackwards "At the plug we are getting about 10.5v on settings 1-3"
Voltage on low should be around 4v and bm will operate. Easy to test blower motor direct to battery +/-

 

 

new resistor did nothing.

 

It's got me stumped. When I check the plug I have 13+ volts with the engine running.

If I plug in the fan I get 0.

I ordered a new fan too from Amazon since the other looks original.

Still nothing

 

Any more ideas?

 

Blower motor requires positive(+) and ground(-)! No need to replace BM before you test it with positive and ground leads! Did you swap relay #87 with #88? Did you check for ground at the BM? Did you check G105?

 

OK we did more diagnostics. We have power at every fuse. We have power at the plug but it appears to not be enough.

We wired a ground to the orange blower plug and ran a + straight from the battery and got it to run.

When we ran the + brn to the fan and the - straight to ground nothing.

Oddly when I test the brn we have 12V with a multimeter and the circuit tester also lights up.

Also tried swapping the relay on the motor with one off a mower. It fit but I am not 100% positive that it is the same style.


Ideas?

 

Mower relay?
Switch HVAC control to HIGH SPEED and check for ground(-) at the black(BK) connector to the HIGH SPEED RELAY.