fan doesn't work

[DetroitRad]

Just wondering if anybody has faced a similiar problem. The fan quit working on me. I checked the owner's manual and it said the problem could be caused by a dirty passenger side air filter. I pulled it and yes its dirty. I put the car back together thinking no filter is like a clean filter, but no good. Fan still doesn't work. Checked the fuse for HVAC and its good. There are 3 resistors labeled "fan", but they are labeled Fan 1, Fan 2 and Fan 3. Does anybody know which one I need to replace? Or is there a "tester" out there that allows you to see if resistors are bad?
Thanks.

[GTP Dad]

If you are talking about the HVAC fan can you tell us how it went out. Did you lose one speed at a time or did they all fail at once? Was there noise from the fan motor or just didn't come on? All these will help to answer your question. Also what year and do you have manual or automatic temp control?

[DetroitRad]

It appeared to die after I turned on the defroster to get some moisture off the windsheild. At least thats the only event that I can tie it to. All speeds failed at once. A/C, heated seats, and rear defroster lights all come on and appear to be working. There is no noise coming from the fan motor. I have a 2004 Grand Prix and it is manual temp control.

[GTP Dad]

Check the fuse in the fuse panel inside the passenger comparment. There should be one for the fan. The relays you are speaking of are for the engine fans not the hvac fan. I would expect you have a blown fuse.

[DetroitRad]

Yep, did that yesterday. I had replaced the 10amp fuse labeled "HVAC" even though it didn't look blown. Still didn't work. Thanks for your replies.

[GTP Dad]

If the fuse is good and the fan still doesn't work then there are a couple of possibilities. One, the fan motor itself has seized up or the control resistor fried itself. Of course another possibility is that something is stuck in the fan preventing it from turning. You may want to pull the fan to see if it works when voltage is applied. If not then the motor is probably shot. If it does then there has to be a problem with the wiring or the resistor. Sorry it wasn't something simpler.

[DetroitRad]

Oh well....I really appreciate your responses to my questions though.

[BNaylor]

I don't normally give my 2 cents worth on '04 and up Grand Prixs but does he have a manual HVAC or digital climate control system.

As GTPDad suggested you'll need to do some serious troubleshooting if you want to resolve the problem yourself without taking it to a dealer. A digital multimeter will come in handy. BTW - Is it still under any warranty either bumper to bumper or extended?

BTW - The '04 and up uses a blower motor module and there is also a blower motor relay which should be checked to see if it is energizing.









Thrasher CAI, DHP v1.0 PCM, SLP Headers,
3.25 SC pulley, CAIT GMAF, 2.5 DP/Hi-Flow CAT,
u-bend delete, 160 TS, ZZP Stage 1 72mm TB,
TB spacer, MSD 8.5mm wires, Autolite 103,
Goodyear Gatorback Serp. & SC Belt,
Nitto NT555R Drag Radials
1/4 ET: 13.210 sec. @ 104.490 mph
0 - 60 ft: 1.945 sec.

[DetroitRad]

Manual. No warranty. Bought it used.

[BNaylor]

The circuits between a '04 and '97 - '03 are similar. You're not getting anything blower wise in the highest speed setting, right?

GM uses a blower motor relay in all applications. It is used to bypass the blower motor resistor or blower motor control module during high speed blower operation. When setting is in high the blower motor relay energizes applying direct battery voltage to the blower motor.

So if you have nothing in the highest setting the possibilities are the blower motor itself as GTPDad suggested or an obstruction at the blower motor squirrel cage or possible wiring or voltage problems. Good luck!








Thrasher CAI, DHP v1.0 PCM, SLP Headers,
3.25 SC pulley, CAIT GMAF, 2.5 DP/Hi-Flow CAT,
u-bend delete, 160 TS, ZZP Stage 1 72mm TB,
TB spacer, MSD 8.5mm wires, Autolite 103,
Goodyear Gatorback Serp. & SC Belt,
Nitto NT555R Drag Radials
1/4 ET: 13.210 sec. @ 104.490 mph
0 - 60 ft: 1.945 sec.

[Tech_n]

I have a 98 Grand Prix GT

1. When I start the car and turn the temp control to 1-4-I do not hear anything.
2. When I turn the temp control to 5, I hear the fan motor blowing

What do this mean because I am lost

Sometimes when I turn the car to 1, the auto lights on the car go off, like the main headlights, but the sidemarker lights stayt on. When I leave it like that and turn the light switch on, all the lights come on. What do that mean.

[BNaylor]

Originally Posted by Tech_n

I have a 98 Grand Prix GT

1. When I start the car and turn the temp control to 1-4-I do not hear anything.
2. When I turn the temp control to 5, I hear the fan motor blowing

What do this mean because I am lost

Sometimes when I turn the car to 1, the auto lights on the car go off, like the main headlights, but the sidemarker lights stayt on. When I leave it like that and turn the light switch on, all the lights come on. What do that mean.

If you have a manual HVAC system its a bad blower motor resistor. If its a dual digital climate control system it a bad blower motor control module.







Thrasher CAI, DHP v1.0 PCM, SLP Headers,
3.25 SC pulley, CAIT GMAF, 2.5 DP/Hi-Flow CAT,
u-bend delete, 160 TS, ZZP Stage 1 72mm TB,
TB spacer, MSD 8.5mm wires, Autolite 103,
Goodyear Gatorback Serp. & SC Belt,
Nitto NT555R Drag Radials
1/4 ET: 13.210 sec. @ 104.490 mph
0 - 60 ft: 1.945 sec.

[richtazz]

Like Bob said, you need a blower resistor. For manual A/C, the delco part number is 15-80464

[B.A.F.]

Originally Posted by Tech_n

I have a 98 Grand Prix GT

1. When I start the car and turn the temp control to 1-4-I do not hear anything.
2. When I turn the temp control to 5, I hear the fan motor blowing

What do this mean because I am lost

Sometimes when I turn the car to 1, the auto lights on the car go off, like the main headlights, but the sidemarker lights stayt on. When I leave it like that and turn the light switch on, all the lights come on. What do that mean.

I have a similar problem with my 2000 GP with manual A/C. Becuse of the daytime running lights going out when I turned the fan on, I tried changing the BCM. Didnt work. The rear def. doesnt work either. One post on the forum said the ignition switch is bad. Did you resolve your problem?