Two Fan Issues
03-20-2017, 10:55 AM
#1
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Car: 89 Formula 350 Original Owner
Engine: 5.7
Transmission: 700R4
Axle/Gears: 3.27
Two Fan Issues
I have two problems is anyone can help point me in the right direction.
1988 GTA with push button climate control
1) Climate control blower fan will only work when the "high" button speed is pushed. The other speed buttons light comes on when pushed but the fan turns off.
2) Passenger side electric cooling fan stays on all the time. No matter what I do I can't seem to find a way to turn it off.
Thanks in advance for any suggestions.
-Kirk
1988 GTA with push button climate control
1) Climate control blower fan will only work when the "high" button speed is pushed. The other speed buttons light comes on when pushed but the fan turns off.
2) Passenger side electric cooling fan stays on all the time. No matter what I do I can't seem to find a way to turn it off.
Thanks in advance for any suggestions.
-Kirk
03-20-2017, 11:06 AM
#2
Re: Two Fan Issues
Sounds like the switch is bad causing the ecm to think ac is requested.
Power from the fan switch goes to the blower motor resister located under the hood in the blower housing. High is full power to the motor relay . All other speeds modes go through the resisters as seen on the schematic. The ecm controls the fan relay located on the drivers side next to the master cylinder. If not found there it might be next to the radiator on the core support.
When fan request is the ecm grounds the fan relay to turn on the secondary fan.
http://austinthirdgen.org/mkportal/m..._continued.gif
See schematic for secondary fan control, not pictured the head switch between cylinder 6&8 if grounded the fan will come on . This is a grey wire, not to be confused with the fuel pump relay grey wire power to the pump.
https://www.thirdgen.org/forums/dfi-...r-ecm-bad.html
Power from the fan switch goes to the blower motor resister located under the hood in the blower housing. High is full power to the motor relay . All other speeds modes go through the resisters as seen on the schematic. The ecm controls the fan relay located on the drivers side next to the master cylinder. If not found there it might be next to the radiator on the core support.
When fan request is the ecm grounds the fan relay to turn on the secondary fan.
http://austinthirdgen.org/mkportal/m..._continued.gif
See schematic for secondary fan control, not pictured the head switch between cylinder 6&8 if grounded the fan will come on . This is a grey wire, not to be confused with the fuel pump relay grey wire power to the pump.
https://www.thirdgen.org/forums/dfi-...r-ecm-bad.html
Last edited by Tuned Performance; 03-20-2017 at 12:00 PM. Reason: Fan information
03-20-2017, 12:28 PM
#3
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Car: 89 Formula 350 Original Owner
Engine: 5.7
Transmission: 700R4
Axle/Gears: 3.27
Re: Two Fan Issues
Thanks! I'll check out the links you sent me tonight. I did put a new resistor in. Here is the link:
http://m.autozone.com/cooling-heating-and-climate-control/blower-motor-resistor/dorman-blower-motor-resistor//pontiac/trans-am/1988/8-cylinders-8-5-7l-fi-ohv/530468_0_0?location=
Im guessing the same resistor works for the push button and the regular type climate controls? If not what should I purchase?
http://m.autozone.com/cooling-heating-and-climate-control/blower-motor-resistor/dorman-blower-motor-resistor//pontiac/trans-am/1988/8-cylinders-8-5-7l-fi-ohv/530468_0_0?location=
Im guessing the same resistor works for the push button and the regular type climate controls? If not what should I purchase?
03-20-2017, 12:32 PM
#5
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Car: 89 Formula 350 Original Owner
Engine: 5.7
Transmission: 700R4
Axle/Gears: 3.27
Re: Two Fan Issues
Gotcha. I installed the resistor like is in the link but it didnt help any. 