Cooling fan relay
12-20-2009, 09:06 PM
#1
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Cooling fan relay
Hey everyone,
I used Clark's procedure to see what was wrong with my cooling fans. After following the procedure I found out the fans no longer work on low speed. I first started to suspect there was something wrong when I realized the fan would not keep on working after I turn off the ignition. According the Clark's may relay would be responsible. I did pull it out and opened it to see if there was anything wrong with it with no luck. Looking for a replacement I see that there is a slight difference in part number. Mine is 944-615-104-01 and I see 944-615-104-03-M100 offered. Which one do I need and is there an alternative to a $$$$ replacement.
I used Clark's procedure to see what was wrong with my cooling fans. After following the procedure I found out the fans no longer work on low speed. I first started to suspect there was something wrong when I realized the fan would not keep on working after I turn off the ignition. According the Clark's may relay would be responsible. I did pull it out and opened it to see if there was anything wrong with it with no luck. Looking for a replacement I see that there is a slight difference in part number. Mine is 944-615-104-01 and I see 944-615-104-03-M100 offered. Which one do I need and is there an alternative to a $$$$ replacement.
12-21-2009, 03:35 PM
#4
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12-23-2009, 05:00 PM
#6
Three Wheelin'
I think you may have a bad resistor. Search is your friend...
The fans are controlled by the relay which receives open/closed circuits from the thermo switch, and refrigerant temp switch. (Possibly the a/c control switch too, but need to review the wiring diagram again).
You should always have power available to the relay, so the fans can run at any time. If the fans are not running, ignition switch off, a/c switch off, and you turn the ignition switch to acc and they starting running, something is wrong.
First thing to do is check for voltage...
Turn off the ignition and remove the cooling fan relay.
1. Check for voltage at positions 30 M1 and 30 M2, you should get 12v + at both positions. If no voltage, check the wiring from the battery, the connections to the fuse panel, and the fuse panel itself. You will have to pull the fuse panel up. Disconnect the battery before messing with the fuse panel.
2. Next check for continuity between ground and the temp switch position on the fuse panel. If you have continuity, the thermo switch is calling for fan operation. If the car is cold, the thermo switch is bad.
3. Fabricate a jumper wire with flat blade connectors on each end, and a 20a fuse in the middle.
4. Connect M1 30 to M1, the drivers fan should run at high speed. Next, jumper between M1 30 and M2, the passenger fan should run at high speed. If both of these are not true, chase down the wiring, or check the fan motor.
5. Next jumper between M2 30 and V1, the drivers fan should run at low speed. Next jumper between M2 30 and V2, the passenger fan should run at low speed. If you do not get low speed operation, the resistors are probably bad, but it could be wiring.
If these tests all check out OK, the relay is bad.
The fans are controlled by the relay which receives open/closed circuits from the thermo switch, and refrigerant temp switch. (Possibly the a/c control switch too, but need to review the wiring diagram again).
You should always have power available to the relay, so the fans can run at any time. If the fans are not running, ignition switch off, a/c switch off, and you turn the ignition switch to acc and they starting running, something is wrong.
First thing to do is check for voltage...
Turn off the ignition and remove the cooling fan relay.
1. Check for voltage at positions 30 M1 and 30 M2, you should get 12v + at both positions. If no voltage, check the wiring from the battery, the connections to the fuse panel, and the fuse panel itself. You will have to pull the fuse panel up. Disconnect the battery before messing with the fuse panel.
2. Next check for continuity between ground and the temp switch position on the fuse panel. If you have continuity, the thermo switch is calling for fan operation. If the car is cold, the thermo switch is bad.
3. Fabricate a jumper wire with flat blade connectors on each end, and a 20a fuse in the middle.
4. Connect M1 30 to M1, the drivers fan should run at high speed. Next, jumper between M1 30 and M2, the passenger fan should run at high speed. If both of these are not true, chase down the wiring, or check the fan motor.
5. Next jumper between M2 30 and V1, the drivers fan should run at low speed. Next jumper between M2 30 and V2, the passenger fan should run at low speed. If you do not get low speed operation, the resistors are probably bad, but it could be wiring.
If these tests all check out OK, the relay is bad.
10-18-2012, 08:59 PM
#7
Racer
Did you mean to write this:
4. Connect M1 30 to M1, the drivers fan should run at high speed. Next, jumper between M2 30 and M2, the passenger fan should run at high speed. If both of these are not true, chase down the wiring, or check the fan motor.
5. Next jumper between M1 30 and V1, the drivers fan should run at low speed. Next jumper between M2 30 and V2, the passenger fan should run at low speed. If you do not get low speed operation, the resistors are probably bad, but it could be wiring.
4. Connect M1 30 to M1, the drivers fan should run at high speed. Next, jumper between M2 30 and M2, the passenger fan should run at high speed. If both of these are not true, chase down the wiring, or check the fan motor.
5. Next jumper between M1 30 and V1, the drivers fan should run at low speed. Next jumper between M2 30 and V2, the passenger fan should run at low speed. If you do not get low speed operation, the resistors are probably bad, but it could be wiring.
