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I have a 1989 corvette. It has a secondary fan. The ac fan. It doesn't come on at all. Can someone please help me! I've posted this 3 times on the forum but no help yet. I need to know where to start looking to help diagnose it. I don't know if it has a fuse under hood r where it's at. I don't know where the relay is or how to test it. I wud greatly appreciate any help!!
thanks!
Are you talking about the fan out front of the Radiator, if so that is what I call a mayday fan(Auxiliary Cooling Fan)it only kicks on under Very High Coolant Temperature like 235 degrees +-
From: Clifton Park, NY ............Clearwater, FL ... 85 Original Owner
Originally Posted by Kmoylan
I have a 1989 corvette. It has a secondary fan. The ac fan. It doesn't come on at all. Can someone please help me! I've posted this 3 times on the forum but no help yet. I need to know where to start looking to help diagnose it. I don't know if it has a fuse under hood r where it's at. I don't know where the relay is or how to test it. I wud greatly appreciate any help!!
thanks!
You've been told that the seconday fan doesn't come on until very hot. Unless you are just about overheating it's not supposed to come on.
Take the radiator out and clean if you want cooler. This is possibly the way yours looks and you can't clean unless out
Last edited by Cruisinfanatic; Jul 17, 2021 at 11:39 PM.
Thank you all for your reply. But the fan I'm talking about won't come on at all. Even when I turn on a.c. where it's supposed to run then. I need someone to tell me how I check it. Where are the fuses and the relay located.
thank all of you for any help.
Kevin
From: Clifton Park, NY ............Clearwater, FL ... 85 Original Owner
Originally Posted by Kmoylan
Thank you all for your reply. But the fan I'm talking about won't come on at all. Even when I turn on a.c. where it's supposed to run then. I need someone to tell me how I check it. Where are the fuses and the relay located.
thank all of you for any help.
Kevin
That's a useful post. The easiest test that I know of though is simply to switch the fan plugs at the relays. If the fan in question does not come on but the other does, you know the fan is bad. If the one that normally works comes on but the other doesn't. it could be a bad relay. Fuses are in the fuse panel and marked,on my '93 at least.
Cheers,
Jerry
Last edited by gdgeorge; Jul 18, 2021 at 09:17 AM.
This is the connector to the sensor for the Aux fan.(On my 87) Unplug it with the key on and ground the end of the connector to the negative side of the battery. If fan comes on the sensor screwed into the head is defective which is the problem 99% of the time. I replaced mine with a main fan sensor from a 1987 Buick Grand National which comes on around which comes on around 210* but as stated you need to check the cooling system, it sounds like you have the typical clogged radiator.
Mine never comes on for my car rarely sees 200*.
How?
1) clean Rad
2) 160* Tstat
3) Fresh coolant
4) Main fan programmed (PROM re-flash) to come on sooner.
My car is a '93 with an LT1 and is different than yours but mine are located driver's side front, right up by the fans ("A"). "B" is an analog temp sensor that runs the main fan installed when I was having issues with the ECM. I just haven't got around to seeing if the fan issue is resolved. (If it ain't broke...)
Your life will be easier, BTW, if you pick up a factory service manual for that beast. Someone here was selling .pdf versions but you can get hard copies on eBay. Around here there are only two or three garages that are capable of working on my car and they charge shop rate at best. And I've had to clean up after one of them more than once...
I too have the Auxiliary fan on my C4. It is easy to test like mentioned above. On my 1988 C4 it is a Green wire with White stripe that connects to the temperature sensor (Switch) between cylinders #1 and #3. All the switch does is ground the wire which completes the circuit for the fan. I have a toggle switch on mine to control the fan manually to help keep the Corvette Happy in traffic.
If the fan is not working you can simply apply power to the fan harness and see if it starts and how much it draws while starting.
C4 vette
