Thread: 2008 Grand Prix - No blower motor

Ok, I have been diagnosing this all day for 3 days now. I have no blower motor on any setting.

Here is what I have done;

Tested voltage at blower motor. I got .8v on full speed, and 2.4v on lowest setting(same when off).

Tested voltage going into resistor/blower motor control module. I got full 12.9 volts using the ground on the plug. So power and ground on the plug are good.

Replaced resistor. Still nothing. After I replaced resistor I checked voltage at the blower motor again to see if maybe blower motor was bad too and I got the exact same readings as before.... .8v on high and 2.4v on low.

Replaced motor for the hell of it with a known good one and got nothing.

Replaced switch controls for the hell of it and got nothing. No change.

Replaced connectors and wires for resistor and blower motor, I though maybe a wire fried in one of the connectors. No change.


WHAT AM I MISSING???!

Thanks in advance!

Which wire on the connector for the control switch is the ground for the speed knob?

Any thoughts greatly appreciated at this point. The only possible thing left that I can think of is mentioned in the last post. Maybe the ground at the switch control itself has a bad ground?

You replaced the dash HVAC and the resistor and connector, did you replace the entire wire run?

Its sounding like a short somewhere in the harness to the blower.

Does the car have the dualzone climate controls or the normal dash controls?

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I just basically replaced the connectors but I did check continuity and everything checks out.

I have the normal controls not dual climate.

I did notice something later on tonight. I do actually get a full 12v at the blower connector, with the car off, until the second that I actually connect the blower. When I connect it, it spins a very very small amount just giving it a nudge, then stops and then the voltage reads around .5v until I unplug everything and try again.

Any ideas

You get 12 at the blower plug with the car off? Or the blower off?

If you are getting full 12 at a plug that usually requires the switch to be on/car to be on you have a short or wrong connection. Further, if I remember correctly, you should see full power at the plug only when the fan controller is turned all the way up, as it uses reduced power to spin at a lower RPM.

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