Cooling Fan Questions
Thread Starter
4th Gear
Joined: Jun 2003
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From: Derby KS
Cooling Fan Questions
I have a 1991 and the cooling fan problem. If I turn the A/C on the fan comes works. Is the the Aux fan? I recently replaced the coolant sensor (under the t/b). Is this the one that controls the fan? or is there another one that controls the fan. Am I wrong in assuming that the relays are ok if the fan comes on with the A/C? Thanks for the help.
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From: Canton GA
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Re: Cooling Fan Questions (maberle2)
Niether sensor really controlls the fan, the ECM controls them. A couple of questions:
1. Why did you have to replace the sensor?
2. What temps are you expecting the fans to turn on?
If turning on the A/C turns both fans on, then the control circuitry is working properly. The only other thing to look at is the "Fan Request" from the ECM, but you'll need a scanner to do that (like Diacom).
BTW, Welcome to the forum! :cheers:
1. Why did you have to replace the sensor?
2. What temps are you expecting the fans to turn on?
If turning on the A/C turns both fans on, then the control circuitry is working properly. The only other thing to look at is the "Fan Request" from the ECM, but you'll need a scanner to do that (like Diacom).
BTW, Welcome to the forum! :cheers:
Thread Starter
4th Gear
Joined: Jun 2003
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From: Derby KS
Re: Cooling Fan Questions (ShawnZR-1)
I replaced the sensor becuase the Temp gage quit working, then I realized that the sensor for the gage is on the right side of the engine, and the wire was off. (must have bumped it when I changed the plugs and it vibrated loose) Now the temp gage works again. I have a hypertech chip installed along with a 170 degree thermostat. This has been in the car for the last couple of years with no problems.
Thanks for the help! and I'm glad I joined the forum
Thanks for the help! and I'm glad I joined the forum
Race Director
Joined: Oct 2001
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From: Canton GA
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St. Jude Donor '03-'05-'06-'10-'11-'12
Re: Cooling Fan Questions (maberle2)
Ok, I'm stepping just a bit outside my league now, I'm not a L98 guru. I'm going to defer to the more experienced now.
I'm just not sure if the later L98 engines used a temp switch or the ECM (LT1's used the ECM to control all aspects of fan control).
Anyone want to jump in?
I'm just not sure if the later L98 engines used a temp switch or the ECM (LT1's used the ECM to control all aspects of fan control).
Anyone want to jump in?
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Re: Cooling Fan Questions (ShawnZR-1)
The main fan is controlled entirely by ECM, the secondary fan is not and comes on when you hit 238F.
My AC doesnt even work right now so i dont know if the Aux comes on with the AC. I know the main fan does.
My AC doesnt even work right now so i dont know if the Aux comes on with the AC. I know the main fan does.
