Blower motor resistor

[brianboetefuer]

I replaced the blower motor resistor because speed selections 1-5 would not work. Now the selections 1-4 work but the number 5 setting does not work. Was just wondering if there could be another problem or is it possible that I got the wrong part from the dealership. Any suggestions would be very helpful.
Thanks

[BNaylor]

Possible you got the wrong part or the blower hi-speed relay also located on the blower motor resistor is not getting the 12 volts from battery supply which is there regardless of whether the ignition is on or off. Might have to troubleshoot by checking input voltage with a DMM just to be sure.

Another possibility is the ground from the climate control unit position 5 is missing to the blower hi-speed relay.

Also, please post the year of your GP in the thread so others can see it easily.

[brianboetefuer]

The car is a 2002 Grand Prix GT.
Thanks

[tblake]

Did you check all the fuses? Dont some fuses use a different supply for the high speed position? (not sure if gp's are this way)

[BNaylor]

Tblake is correct. That is a fused circuit. So check the HVAC HI fuse which is 30 amps located at the fuse box by the glovebox. 4th row down, last fuse to the right. This will only affect fan speed position 5.

[izzy24]

I'm having the same issue on my 02 GT. But my hi speed works and will only work with defrost.

[BNaylor]

Originally Posted by izzy24

I'm having the same issue on my 02 GT. But my hi speed works and will only work with defrost.

Just to be sure or clarify are you saying you're missing fan speeds position 1-4 or just 5 and air is only coming out of the defrost vents?

Common problem for improper vent control is a leaking or bad vacuum line from the intake manifold.

[brianboetefuer]

I check the fuses and they are all good, I did try replacing the mini relay for the same circut but that did not work either. Just checking if there is something that I am overlooking or if it could be in control on the dash. How hard is it to get a the dash apart to check if everything is hooked up.
Please let me know.
Thanks

[doctorhrdware]

Also check the wiring for the blower motor resistor, I had the orange wire-battery feed wire, and the black wire-ground wire, both wires melted. The blower motor resistor terminals corresponding to those wire also melted. As to why this happened, I have not figured that one out yet. The fuse for this circuit did not blow which is also interesting. I have replace the blower motor resistor, and I am waiting for the female connector and pin to be delivered on Monday to complete the repair.

[izzy24]

Yes, I have only speed 5 and now can only use the defrost setting to get any heat or air.