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Blower motor resistor?

Tiny
YANNIJ01
  • MEMBER
  • 2005 PONTIAC GRAND PRIX
  • 3.8L
  • 6 CYL
  • FWD
I am having a problem with the blower motor resistor. I went through a car wash the other day. The day after that my blower motor didn't work. I removed the blower motor. Hooked it up to a 12V battery. Motor ran fine. I then checked the 30amp Batt3 fuse within the engine compartment. The fuse was blown. I replaced the fuse and the blower ran even with the car off. I then replaced the resistor. Everything seemed to run fine that evening, tested a few times. Turned off and started car a few times, no problems. The next morning (about 0 degrees) started car, no blower. Checked fuse, blown fuse, also blew the resistor. Went to a different parts store. They inform me there are 2 different resistors.(One auto climate, one not) Buy another resistor and install, replace fuse. Works good again, started car 4 times, all good. This morning (5 degrees) started car no blower.
Any suggestions?
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Wednesday, February 12th, 2014 AT 3:17 PM

56 Replies

Tiny
HMAC300
  • MECHANIC
  • 48,601 POSTS
There is a tsb on this its' caused form the wiper motor so i'm including on how to fix it.
Some customers may comment on an inoperative or intermittent Heating, Ventilation and Air Conditioning (HVAC) blower motor. Others may comment that the blower motor speed may momentarily drop or that the blower motor continues to run after the key is turned off.
Cause
This condition may be caused by a voltage spike from the wiper motor. The voltage spike may cause a logic lock up in the blower motor control module that may be either momentary or permanent.
Correction
Correction
DO THISDON'T DO THIS
Install a Capacitor at the Blower Motor Control Module ConnectorDO NOT replace the Blower Motor Control Module, Blower Motor or the HVAC Control Head

Technicians are to install a capacitor, P/N 25073556, at the blower motor control module connector using the following procedure:
Disconnect the negative cable from the battery. Refer to the Battery Negative Cable Disconnect/Connect procedure in the Engine Electrical section of SI.
Remove the right closeout/insulator panel. Refer to the Closeout/Insulator Panel Replacement-Right procedure in the Instrument Panel, Gages and Console section of SI.
Disconnect the wire harness connector to the blower motor control module
Some customers may comment on an inoperative or intermittent Heating, Ventilation and Air Conditioning (HVAC) blower motor. Others may comment that the blower motor speed may momentarily drop or that the blower motor continues to run after the key is turned off.
Cause
This condition may be caused by a voltage spike from the wiper motor. The voltage spike may cause a logic lock up in the blower motor control module that may be either momentary or permanent.
Correction
Correction
DO THISDON'T DO THIS
Install a Capacitor at the Blower Motor Control Module ConnectorDO NOT replace the Blower Motor Control Module, Blower Motor or the HVAC Control Head

Technicians are to install a capacitor, P/N 25073556, at the blower motor control module connector using the following procedure:
Disconnect the negative cable from the battery. Refer to the Battery Negative Cable Disconnect/Connect procedure in the Engine Electrical section of SI.
Remove the right closeout/insulator panel. Refer to the Closeout/Insulator Panel Replacement-Right procedure in the Instrument Panel, Gages and Console section of SI.
Disconnect the wire harness connector to the blower motor control module
Some customers may comment on an inoperative or intermittent Heating, Ventilation and Air Conditioning (HVAC) blower motor. Others may comment that the blower motor speed may momentarily drop or that the blower motor continues to run after the key is turned off.
Cause
This condition may be caused by a voltage spike from the wiper motor. The voltage spike may cause a logic lock up in the blower motor control module that may be either momentary or permanent.
Correction
Correction
DO THISDON'T DO THIS
Install a Capacitor at the Blower Motor Control Module ConnectorDO NOT replace the Blower Motor Control Module, Blower Motor or the HVAC Control Head

Technicians are to install a capacitor, P/N 25073556, at the blower motor control module connector using the following procedure:
Disconnect the negative cable from the battery. Refer to the Battery Negative Cable Disconnect/Connect procedure in the Engine Electrical section of SI.
Remove the right closeout/insulator panel. Refer to the Closeout/Insulator Panel Replacement-Right procedure in the Instrument Panel, Gages and Console section of SI.
Disconnect the wire harness connector to the blower motor control module
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Wednesday, February 12th, 2014 AT 3:29 PM
Tiny
YANNIJ01
  • MEMBER
  • 2 POSTS
Thank you for the fast response. I have ordered that part and I will let you know if that works. I appreciate your help. Can I donate at any time?
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Wednesday, February 12th, 2014 AT 5:12 PM
Tiny
HMAC300
  • MECHANIC
  • 48,601 POSTS
I am unsure about that contact them and ask as I only answer questions an ddo nothing on that end. Contact is on the information area at bottom of page. Hope it works for you.
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-1
Thursday, February 13th, 2014 AT 6:22 AM
Tiny
DMHOLLAND06
  • MEMBER
  • 4 POSTS
  • 2004 PONTIAC GRAND PRIX
  • FWD
  • AUTOMATIC
  • 60,000 MILES
For some reason, the blower in my 2004 Pontiac Grand Prix continues to blow cold air even after I remove the keys from the ignition. The only way I can make it stop is to disconnect the battery. I tried removing some of the relays (the ignition and the ac compressor) and none of the fuses look bad. I do not know what to do. Could it be the blower motor/resistor? When the car is on the heat still works and it will blow on high regardless of the inside setting.
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Monday, August 3rd, 2020 AT 11:33 AM (Merged)
Tiny
JDL
  • MECHANIC
  • 16,098 POSTS
The blower relay may be part of the resistor assembly? You may have to replace as a unit. I haven't looked at the partsbook, to see if relay is separate.
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Monday, August 3rd, 2020 AT 11:33 AM (Merged)
Tiny
DMHOLLAND06
  • MEMBER
  • 4 POSTS
Is there any way to tell if it is just the blower motor resistor that is bad or if its a relay or both? I checked and there is still power going to the fuse area for the heater blower when the car is off if that helps at all. I am just hoping there is not a short in the car somewhere.
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Monday, August 3rd, 2020 AT 11:33 AM (Merged)
Tiny
JDL
  • MECHANIC
  • 16,098 POSTS
I looked at your wiring info again, 04 grand prix GT, there is no relay. I must have looked at the wrong model or year, earlier. There are three fuses that send voltage to the hvac, two of them are hot all the time. Check for any hvac trouble codes.
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Monday, August 3rd, 2020 AT 11:33 AM (Merged)
Tiny
RHAE52
  • MEMBER
  • 1 POST
  • 2004 PONTIAC GRAND PRIX
  • 220,000 MILES
The blower fan is intermittent, it will go out when you hit a bump and then starts back up when you tap the top of dash - above the radio. There is voltage going to the blower motor and the air flow can be adjusted from low to high. If you hit the blower motor, it does not stop/start. Another issue that cropped up, is when the key is in the 'on' position, all the lights on the console will flash on/off for a second, which never occurred before. At first I thought it was the blower motor, but because of the flashing lights and hitting the top of the dash, I am wondering is this a loose connection or a problem with the ignition module?
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Monday, August 3rd, 2020 AT 11:33 AM (Merged)
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,700 POSTS
It sounds like a loose wire. Check the wiring on the blower motor itself. Make sure it has a good ground and everything is clean and tight. As far as the resister, you would only have high speed and you said they all work.
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Monday, August 3rd, 2020 AT 11:33 AM (Merged)
Tiny
RSMITH3865
  • MEMBER
  • 1 POST
  • 2003 PONTIAC GRAND PRIX
  • 6 CYL
  • FWD
  • AUTOMATIC
  • 32,000 MILES
Where is the Blower Motor Resistor Pack located?
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Monday, August 3rd, 2020 AT 11:33 AM (Merged)
Tiny
SATURNTECH9
  • MECHANIC
  • 30,869 POSTS


https://www.2carpros.com/forum/automotive_pictures/416332_2003_pontiac_grand_am_blower_motor_resistor_1.jpg


Remove the right side instrument panel insulator.
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Monday, August 3rd, 2020 AT 11:33 AM (Merged)
Tiny
INDIANAWMN7798
  • MEMBER
  • 6 POSTS
  • 2002 PONTIAC GRAND PRIX
  • RWD
  • AUTOMATIC
I have a 2002 Pontiac Grand Prix. It has not had any heat or A/C for the past year. I have replaced the following in this order:

*Checked and replaced all fuses related to HVAC system (checked each before and after with test light)
*Replaced ignition switch (tested with multimeter, has continuity)
*Replaced control unit (head unit) (tested with multimeter, has continuity)
*Replaced blower (jumped with battery, works)
*Replaced resistor (tested with multimeter, has continuity)

After replacing these parts, I still have no heat or A/C. I have gone through with a test light and tested all power and connections. Everything is good until I get to the connector that attaches to the resistor. There is an orange wire to the far left of the connector that when I touch it with the test light, it has power. I check all the other wires in the connector, I get nothing. Even when I change the fan speeds on the head unit and use the test light on the connector, I get nothing. Just power to the orange wire on the far left side of the resistor connector. I have also jumped the blower motor and it works just fine, no problems. Even used a multimeter (or a volt tester) to make sure everything gets power and everything tests fine. Just get absolutely no power to any fan speeds on the resistor connector. The connector has 7 female slots (I hope I explained that correctly) and the car has dual climate control. I know the head unit has power, it turns the actuator door when you change where the air is blowing (floor, windows, etc) and when you switch from heat to a/c you can hear the door turn. The rear defrost works as well, which is the only thing that works as far as any defrost or heat is concerned. My mechanic has checked the thermostat as well as flushed my coolant system so there are no leaks and it doesn't and has not ever overheated since I have had it.

I have searched and searched for diagrams or how-tos on how to replace the wiring harness for the resistor or even how to replace the connector and have come up with nothing. I am hoping for some insight as to what I could do next. My next step is to test each wire coming out of the wiring harness without the connector attached to see if it is a faulty connector. But I wanted to make sure first before taking that step.

If you need any other information please let me know.
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Monday, August 3rd, 2020 AT 11:33 AM (Merged)
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
Ok, if you have power to the orange wire at the resistor, then there should be power to the one side of the blower motor. It is a ground control circuit. Thats why you donr see any voltage with your meter and test light. Check the diagram I sent you and be sure both fuses are good. Check the HVAC cntrl fuse for power.

Roy
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Monday, August 3rd, 2020 AT 11:33 AM (Merged)
Tiny
INDIANAWMN7798
  • MEMBER
  • 6 POSTS
I will definitely check both of those fuses when I get up in the morning with both my test light and fuse tester. I am sure I checked them both but will do so again. My mechanic had also suggested it was possibly the head unit but I have replaced that already.

I will test the fuses in the morning and update you then.

Thank you.
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Monday, August 3rd, 2020 AT 11:33 AM (Merged)
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
Ok
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Monday, August 3rd, 2020 AT 11:33 AM (Merged)
Tiny
INDIANAWMN7798
  • MEMBER
  • 6 POSTS
So I checked the fuses that you recommended this morning and all tested good. I thought maybe it may have been the resistor, because when I tested the orange wire to the far left it tested good, so I decided to use the multimeter and tested both orange wires (they are next to each other) and they tested fine. The other wires I got no reading on. So I went and bought a brand new resistor and plugged that in. Blower is still not blowing on any speed. I had a gentleman in line suggest a toggle switch. Sounds like a bit more work than I know about but I'm not sure if that is a simple alternative than ripping the dash apart to replace the resistor wiring harness.

Any further suggestions or ideas are appreciated.
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Monday, August 3rd, 2020 AT 11:33 AM (Merged)
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
Who said anything about tearing the dash apart for wire harness?
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Monday, August 3rd, 2020 AT 11:33 AM (Merged)
Tiny
INDIANAWMN7798
  • MEMBER
  • 6 POSTS
I was assuming that since it is behind the dash. If that's not the case then I am not sure as to what else I can replace. Sorry I am just not sure where to go from here.
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Monday, August 3rd, 2020 AT 11:33 AM (Merged)
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
Ok, first, hook up the resistor and test for one leg at the blower motor to have 12 volts.

If it does, then good.

Next is to remove the connector and test for voltage from the other 4 wires. The feeds will come from the blower speed switch. Each wire will get a feed from each position of the blower speed switch
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Monday, August 3rd, 2020 AT 11:33 AM (Merged)
Tiny
INDIANAWMN7798
  • MEMBER
  • 6 POSTS
Well at least some good news, one side of the blower motor like you said is getting the 12 volts. Tested all other wires for voltage without the connector and there is nothing.
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Monday, August 3rd, 2020 AT 11:33 AM (Merged)

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