I am trying to get this HVAC stuff figured out after the LSx swap and I can't seem to get the blower motor to work on any setting. Low/Med/High all show nothing on a multimeter attached to where the blower motor would plug in.

I have good voltage at the large red wire (constant hot). As mentioned though the purple wire has no voltage, both at the relay and the blower end. It does not appear to be a ground issue, I used the chassis as a ground for it via the multimeter probe.. Interior controls do have voltage from both feed wires.

What would cause the purple wire to show no voltage, does this sound like a control issue?

 

I noticed something. On the first 2-3 speeds I do see about 2-2.5v on the purple wire, 0v on high speed. That is using a multimeter grounded through the chassis, not the ground wire on the blower connector.

 

yeah I think you need a ground wire from blower case to chasis ground in case you didn't have that. Sounds like you have a switch issue. you have voltage on low med but not high....does the fan blow on low med now?

 

It does not, even when plugged in the blower doesn't move at low/med. I am going to try tomorrow using a ground to chassis WITH the blower hooked up and see if it is a ground issue. Plenty of power at the controls, but it doesn't seem like i am getting much of anything at the blower itself. 2.5v wouldn't even be enough for low/med would it?

Unfortunately the multimeter broke and no longer works for testing continuity or I would know if the grounds are good. The only way I could test the ground was to use the chassis as a ground on the ground probe, and then test the voltage I got with the red probe in the hot side of the circuit - the purple wire. (which showed the 2-2.5v for the purple wire).