Ohtwos500

Fixed one problem now another. So the AC stopped workin the other day. No air out of the vents. Just to make sure i checked everything under the hood and the compressor and fans are coming on like they are supposed to and lines sweating so now i need to look at the blower motor and resistor. What tests can i perform with a meter? I was thinkin test for 12v at the two lead connector going to the blower....sound right?

lganski

If you have no air out of the vents then the blower is not working. Either the blower let go or the "resistor" went bad. You can check the motor just by applying 12 volts to it. It will either run or not. Chances are that you need a new blower regulator which is mounted on the blower motor.

Ohtwos500

Ok so I purchased an aftermarket resistor and installed it, and still no blower operation. I have to do more testing at this point. I metered the 3 wire connector from hvac control head and with ignition on I have 12v at the red hot wire and a good ground at the brown ground wire and 6v at the smaller signal wire with the blower on high speed. With those voltages I figure the control head is working. When I plug that 3 wire connector into the resistor and meter the two leads going to the blower motor Im getting 0 volts. I'm thinking its a defective resistor or is there something I am missing???

lganski

You did not say that the blower motor was working, did you test it while you had it out? Did you check the input voltages after you plugged in the connector to verify you were still getting a signal? If you have a signal going in and nothing coming out you may still have a bad regulator.

Ohtwos500

Ok I'll check input voltages with connector plugged in but do those voltages sound right? 12v b/w the two big wires and a variable 1.5-6v on the small wire depending on speed selection. ???

If these voltages sound right and are present with connector plugged in and I have no voltage on the output then the reg must be bad I would think.

lganski

Does the fan run when you test it without the regulator? It could still be the fan.

Ohtwos500

I don't know if the fan runs testing it without the reg. How can I do that? Apply 12v to it?

Today I'm going to test the reg input voltages at the 3 wires with the connector plugged in.

lganski

The best way to test it is to apply 12V to it to see if it works. Sounds like you have a bad motor. if you don't want to test it just buy a new blower on ebay and be done with it.

Ohtwos500

i checked resistance b/w the two lead connector coming from the motor and its open. shouldnt the blower motor have some kind of resistance?

I also checked the voltage into the regulator with the connector plugged into the reg and im getting batt volatage on the big red and yellow and a good ground on the big brown and the small signal wire im getting 6v with blower in max speed.

Checking the 2 output prongs to the blower im getting 0 volts. Now i wonder if this simply means the reg is bad or does it mean the motor is bad? how can i apply 12v to the blower? can i use a car battery and hookup leads to the motor?

lganski

Yes you can use a car battery and some jumpers to test the motor. You should have read some sort of resistance across the terminals to the motor. An open tells me that the motor let go. Try applying 12 volts to it and see if it spins.


My other concern is that you are not measuring any output from the regulator. Deal with the motor first and make sure it starts when voltage is applied to it. Then you can get back to the regulator.