current flow
 

Hi guys, I'm trying to trace the current flow from under the hood at 30 amp fuse to the hvac blower. the diagram I found does not show where the power comes from to energize the blower relay and I can't find a diagram of the pinouts on the relay itself. Any help, thanks. Thought I'd better add 06 LS, no power to blower motor, ground is fine, has new resister, butle patch done, BCM has been replaced for another problem.

power test the switch itself, it could be the circuit board in the switch

Thanks Blue, I found my relay diagram. Gonna change my name too reelstupid, the diagram is on the side of the relay, relay works. Blue do you have an idea where the brown wire to the blower motor originates. The wiring diagram shows it to be connector C position4 to c219. Do you think this is the large connector in the BCM? I'll keep looking and thank you again.

That would be to the BCM, most times I've seen this issue its the switch as I posted earlier

X2 on the switch being the most likely culprit, rule that out before you start thinking BCM issues.

But just for curiosities' sake, why was the original BCM swapped out, they seldom fail.

Will this help.

The brown wire go's from the blower motor to the relay. From the it receives it power from the under hood fuse box.

Do you have the power feed from the under hood fuse box to the relay inside?

The under hood fuse box is known for lose connections and becoming unlatched from its case over time.

Checked the switch, it has continuity,the relay has B+ on pins 85 and 86, I believe it then flows to pin 30, however applying B+ to pin does not make the fan run. The BCM was replaced for an issue with the security system but did not repair the problem. This was before I got the car, it was given to me. Start again tomorrow. First the fan then the wheel bearings and moog bushings for the lower control arms.

By the way, thank you, Lucky for the wiring diagram and I will check the fuse box.

Remember the body controller only closes the relay that sends power to the blower motor.

The switch and the blower resister controls the speed from the ground side.