A/C Blower
120950
06-26-2005, 10:28 AM
2001 Pontiac Grand Am. Blower for A/C and heater gas quit. Speeds seem to have gone out one at a time. Now none of them work. Any suggestions?
GTP Dad
06-26-2005, 10:58 AM
I moved you thread to the Grand Am forum since your question is about a Grand Am. The problem you have is due to a bad blower motor resistor. The resistor costs about $40 and is located under the dash next to the fan motor. You can replace it yourself but it is quite a confined area.
netzener
06-26-2005, 09:19 PM
If the speeds failed one after the other over a short period of time (a few days or weeks) the root-cause of the problem may be the blower motor. Over-current in the blower motor will destroy the blower resistor. The blower cage could be plugged with debris, or motor bearings or windings are bad.
If the speeds failed over a long period of time (months/years) then you probably only need to replace the blower resistor.
The original design of the blower resistor was roughly 2 inches square with elements etched on both sides of a ceramic substrate. Turns out 2 sq.in. is not enough to disipate the heat from the resistors and they fail over time. When resistor elements fail, they turn dark in spots and the green insulating coating will peel.
The replacement resistor is roughly 3X2 in. with resistors on one side. It will be longer than the resistor you have but will fit properly when installed.
The blower motor resistor is attached to the AC/Heater duct with two hex head screws. To replace the blower motor resistor you WILL need a flexible driver joint to reach the screw closest to the firewall. It is impossible to reach it with a standard nut driver or socket wrench. I use a nut driver and differential socket adaptor.
As mentioned elsewhere on the board, replacement is about an hour but it can be furstrating work due to the location of the resistor. There is a courtesy lamp under the dash that is in just the perfect place for burning your arm.
You will want to plug in the replacement resistor and briefly test that all speeds work before you install the new resistor. Don't run the blower for very long as the blower airflow is needed to cool the resistor. It will get warm fast.
If the blower does not operate on all speeds, make sure the resistor cable if firmly plugged in. Unplug it and plug it in again to make sure connections are good. The connector must be fully seated in order to work properly. Clean the contacts if they are dirty.
If the blower doesn't run on any speed, check that the 20A fuse located inside the right in-dash fuse panel (front passenger side) is good.
Remove the blower motor cable and check that there is 12V at the connector when the speed control is turned to 5 (full). If there is 12V at the blower connector, then your blower motor will need to be replaced.
If there is no 12V at the blower connector, check the AC Blower relay in the engine compartment relay/fuse box (drivers side near the firewall with a single plastic nut holding down the cover). The map inside the relay box indicates the blower relay (large grey box in the top middle). Remove and reinstall this relay to ensure that contacts are good.
If this does not fix the problem, check or replace the blower relay.
If none of this fixes the problem, then you have a more serious wiring harness or speed switch problem. I would refer this problem to a qualified mechanic.
Good luck.
Netzener
If the speeds failed over a long period of time (months/years) then you probably only need to replace the blower resistor.
The original design of the blower resistor was roughly 2 inches square with elements etched on both sides of a ceramic substrate. Turns out 2 sq.in. is not enough to disipate the heat from the resistors and they fail over time. When resistor elements fail, they turn dark in spots and the green insulating coating will peel.
The replacement resistor is roughly 3X2 in. with resistors on one side. It will be longer than the resistor you have but will fit properly when installed.
The blower motor resistor is attached to the AC/Heater duct with two hex head screws. To replace the blower motor resistor you WILL need a flexible driver joint to reach the screw closest to the firewall. It is impossible to reach it with a standard nut driver or socket wrench. I use a nut driver and differential socket adaptor.
As mentioned elsewhere on the board, replacement is about an hour but it can be furstrating work due to the location of the resistor. There is a courtesy lamp under the dash that is in just the perfect place for burning your arm.
You will want to plug in the replacement resistor and briefly test that all speeds work before you install the new resistor. Don't run the blower for very long as the blower airflow is needed to cool the resistor. It will get warm fast.
If the blower does not operate on all speeds, make sure the resistor cable if firmly plugged in. Unplug it and plug it in again to make sure connections are good. The connector must be fully seated in order to work properly. Clean the contacts if they are dirty.
If the blower doesn't run on any speed, check that the 20A fuse located inside the right in-dash fuse panel (front passenger side) is good.
Remove the blower motor cable and check that there is 12V at the connector when the speed control is turned to 5 (full). If there is 12V at the blower connector, then your blower motor will need to be replaced.
If there is no 12V at the blower connector, check the AC Blower relay in the engine compartment relay/fuse box (drivers side near the firewall with a single plastic nut holding down the cover). The map inside the relay box indicates the blower relay (large grey box in the top middle). Remove and reinstall this relay to ensure that contacts are good.
If this does not fix the problem, check or replace the blower relay.
If none of this fixes the problem, then you have a more serious wiring harness or speed switch problem. I would refer this problem to a qualified mechanic.
Good luck.
Netzener
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