Cooling fan issue
#1
Racer
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Cooling fan issue
Is one of the cooling fans to run when the car is cold and the key is turned on?
As I recall, this should not happen. I have run a search on this issue and have run all of the suggested test. Every thing checks out withe the exception of the tranmission sensor of which I can't get any resistance. I have switched out the sensor with the one that was in the car before the fire and still no resistance. I have run a continuity test from the transmission to the control module at the passenger seat and have not had any opens. The fan that runs is on the drivers side, although the WSM indidcates by the wiring color should be on the passenger side. The fan also runs at high speed. This fan runs with the AC switch on and off and with the hood open.
Additional info, their are no fluids in the engine or transaxle. The dashboard wiring harness was repaired after a cat fire, the engine harness was replaced, the engine was pulled and rebuilt.
As always any thoughts are greatly appreciated.
Thanks, Terry
As I recall, this should not happen. I have run a search on this issue and have run all of the suggested test. Every thing checks out withe the exception of the tranmission sensor of which I can't get any resistance. I have switched out the sensor with the one that was in the car before the fire and still no resistance. I have run a continuity test from the transmission to the control module at the passenger seat and have not had any opens. The fan that runs is on the drivers side, although the WSM indidcates by the wiring color should be on the passenger side. The fan also runs at high speed. This fan runs with the AC switch on and off and with the hood open.
Additional info, their are no fluids in the engine or transaxle. The dashboard wiring harness was repaired after a cat fire, the engine harness was replaced, the engine was pulled and rebuilt.
As always any thoughts are greatly appreciated.
Thanks, Terry
#3
Chronic Tool Dropper
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Originally Posted by cambria
Is one of the cooling fans to run when the car is cold and the key is turned on?
As I recall, this should not happen.
As I recall, this should not happen.
I have run a search on this issue and have run all of the suggested test. Every thing checks out withe the exception of the tranmission sensor of which I can't get any resistance. I have switched out the sensor with the one that was in the car before the fire and still no resistance.
The wire runs from the switch through terminal S25 on the main electric panel, then immediately back out of the panel at N23 to terminal 9 on the fan controller by the passenger seat. This wire is common with the intake temp switch on top of the intake manifold, by the way. Pull the wires from that intake switch to make sure you are testing only one thing at a time. I had to put in a new intake switch after I gave the engine a bath once; If you used water to clean the engine it's possible that your switch has the same intermittent-close problem that I had. Pull the wiries off to be sure.
I have run a continuity test from the transmission to the control module at the passenger seat and have not had any opens. The fan that runs is on the drivers side, although the WSM indidcates by the wiring color should be on the passenger side. The fan also runs at high speed. This fan runs with the AC switch on and off and with the hood open.
Additional info, their are no fluids in the engine or transaxle. The dashboard wiring harness was repaired after a cat fire, the engine harness was replaced, the engine was pulled and rebuilt.
As always any thoughts are greatly appreciated.
Thanks, Terry
As always any thoughts are greatly appreciated.
Thanks, Terry
Look also at the temp sensor at the front of the radiator, low on the driver side. If the circuit to this sensor is open, the fans will run immediately on key on. Compare this with the trans and intake temp switches which will run the fans regardless of key position. The sensor is a reverse-coefficient thermistor, so an open or low resistance on that sensor loop indicates that the engine is hot. You can see and reach the connector down in that bottom front driver's side corner of the radiator, around/under the AC condenser. test the resistance of that circuit ithyour ohm meter from terminal 1 on the control unit, measured to ground. You may need to clean the connections at the MP-II ground point, which is adjacent to the jump-start terminal on the pass side inner fender panel. Look for a lot of brown wires converging. (hard to see, up under the fender mounting lip)
HTH!
#4
Under the Lift
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If the temp sensor at the lower driver side front corner of the radiator is disconnected/broken, one fan will run as you are describing. You can see and get to this at the front of the radiator from above.
#5
Racer
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Bob, Thank you for your detailed response. I will start going through the items that you have discussed tomorrow and I will let you know how it goes. Since my last post I have found some additional problems which I am sorting out and correcting.
Bill, Thank you for your post. I have the temp sensor out and will recheck it. Also after reading the posts from SF I noticed that you met my son Kevin.
Bill, Thank you for your post. I have the temp sensor out and will recheck it. Also after reading the posts from SF I noticed that you met my son Kevin.