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Discussion Starter #1
ok i'm working on my 89 sundance t1 auto the fan is always on lol, i have replace the sensor that is in thermastat housing i think its the coolant temp sensor, and swaped computers, i tested the sensor and it seems to work fine the ohm's goes down when the temp goes up on the sensor, like if i hold onto it, i dont want to rig it to work but i am tired of the car not getting to temp lol the heat doesnt work!! untill i unplug the fan and let it warm up, then if i plug it in the temp gauge drops! i am sure there is something am leaving out but its late and i am tired, bit thanks in advanced!:thumb:
 

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stuck relay ?
+2, thing switched on and stayed there lol. Fan relays are cheap and go all the time, same thing they used for decades even on muscle cars.

Your fan control is weak out of the computer, so they run big power to a relay and the weak power source. The weak power source makes the contact for the big power source and the fan comes on. But this is a basic mechanical switch that is prone to failure.:bash:
 

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I also agree on checking relay.
Controller controls the ground side of the relay so if the ground circuit to the relay is shorted to ground the fan will run constantly.
Swap the fan relay with the A/C clutch relay and see if the problem goes away.

Also if the car is in failure the fan will run constantly.
You would have a CEL illuminated unless the lamp is not working.
 

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Discussion Starter #7
the cel is not on and no codes and it waits about 20 seconds after running then turns on, i can get a vid if that wil help lol. bu i will look at the relay, and this might sound stupid but which relay is the fan relay? :bang head:
 

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the cel is not on and no codes and it waits about 20 seconds after running then turns on, i can get a vid if that wil help lol. bu i will look at the relay, and this might sound stupid but which relay is the fan relay? :bang head:
Which sounds exactly like a car in failure.


On an '89, it should be on the driver's side shock tower, beside the fuel pump relay. It will be silver. More Information for STANDARD MOTOR PRODUCTS RY98
The silver relay on the strut tower is the starter relay.
On the L/S fender(driver) there are 3 relays, starting from the front of the car they are...
ASD, A/C clutch, cooling fan

The cooling fan and A/C clutch are intechangable and should have the same part # on the relay.
 

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Discussion Starter #11
oh ok well i'll look at it and see whats going on i havent had a chance to work on it yet. been swamped with others misc projects.

and what do you mean by "a car in failure"lol as much as i think i know what you mean but i wanna ask and make sure
 

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and what do you mean by "a car in failure"lol as much as i think i know what you mean but i wanna ask and make sure
Limp Mode, Failure, CEL Illuminated.
When you disconnect the coolant temp sensor with the engine running to set/check timing the car goes into failure mode and there is a delay and then the cooling fan cycles on.

That is why I asked if the CEL worked.

I would start by swapping the relay.
 

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Terminology changes from manufactuer to manufactuer and year to year, depends what you are working on and who you are talking to.
 

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Stupid fan relays go bad all the time. I have had 3 go back on various td's. Lucky your comp caught that. I have had some cars where it just overheats after a while and the fan never kicks on.
 

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The silver relay on the strut tower is the starter relay.
On the L/S fender(driver) there are 3 relays, starting from the front of the car they are...
ASD, A/C clutch, cooling fan

The cooling fan and A/C clutch are intechangable and should have the same part # on the relay.
Woops. The one on the website has the wrong picture and I didn't even think to whip the book out and verify. Thanks for catching that.
 

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Discussion Starter #18
ss not the relay it works like it should. lol anything besides that or the computer as i dont have an extra i sent it to cindy :D lol and i just bought a new coolant temp it didnt help
 

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Connect a test lamp to + battery and the ground terminal of the fan relay in the relay connector.
If the lamp lights you are connected to ground and the relay is always actuated.
If that is the case either the controller is faulty or the fan control wire is shorted to ground.
To check for a short to ground disconnect the relay connector and the controller connector.
Connect one lead of your ohmmeter to - battery and then probe the fan relay control wire at the relay end and then at the controller end.
The ohmmeter should read open, if it shows continuity on either end the wire is shorted to ground.
If the ohmmeter reads open on both ends of the wire replace the controller.

The cooling fan relay control(ground) wire is DB/PK and runs to the 60 pin connector cavity #57.

You are also sure that the A/C or Defrost is not on which would make the fan cycle with compressor operation.

 

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Discussion Starter #20
Connect a test lamp to + battery and the ground terminal of the fan relay in the relay connector.
If the lamp lights you are connected to ground and the relay is always actuated.
If that is the case either the controller is faulty or the fan control wire is shorted to ground.
To check for a short to ground disconnect the relay connector and the controller connector.
Connect one lead of your ohmmeter to - battery and then probe the fan relay control wire at the relay end and then at the controller end.
The ohmmeter should read open, if it shows continuity on either end the wire is shorted to ground.
If the ohmmeter reads open on both ends of the wire replace the controller.

The cooling fan relay control(ground) wire is DB/PK and runs to the 60 pin connector cavity #57.

You are also sure that the A/C or Defrost is not on which would make the fan cycle with compressor operation.

i will probe the wires tomarrow i hope its a simple issue, lol and since you said something about heater switch making it turn on makes me think, when i had the car running last time before motor blew the fan didn't do this on at all times thing before with the a/c on or the heat on, i remember the fan kicking on and off like it should:confused:, butv thanks for all the help guy!
 
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