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Discussion Starter #1
My electric cooling fan isn’t coming on. I followed the instructions in the repair manual – If I short out the wire going to the temperature sensor next to the number 6 cylinder, the fan doesn’t activate; if I connect the A and E connectors on the fan relay next to the brake cylinder, the fan activates. Therefore, the instructions say to change the relay. I changed the relay and no change. I check both relays and found that the new one does not close the circuit to energize the fan. And the old one closes the circuit to energize the fan but current won’t flow through it - I can see the relay closed with a ohm meter.

The question is: if the fan circuit is closed (the Ohm meter shows it closed) why won’t the current flow through it?
 

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What year? Does it have an aux fan? If I'm not mistaken, the sender you grounded by the #6 cylinder is just for the guage. If it is an l-98, I think the fan is activated by the computer. The coolant sensor for the computer is located in the front of the engine.
 

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fan

What year? Does it have an aux fan? If I'm not mistaken, the sender you grounded by the #6 cylinder is just for the guage. If it is an l-98, I think the fan is activated by the computer. The coolant sensor for the computer is located in the front of the engine.
Jegs has a adustabile for 26.00 I have one just spliced in to hot wire & fan works fine got it set for 180 it runs for about 1/2 hr after you shut er down!!
 

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Still an 84 like in your profile?

http://misterbill.homeip.net/vette/wiring/cooling_fan.jpg

Its just a Temp switch on 84 for those not familiar.

So you jump the red and blk/red wire and it works. You replaced relay. Here's a couple "silly questions". Did fuse blow since you last checked it?
Is Ignition switch in RUN position? It must be for relay to work. Hey... you never know!

BTW the OEM relay is notoriously untrustworthy. I'd suggest upgrading to the newer one.
 

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Discussion Starter #7
Waiting for parts

Oh, yea... it's a 84 crossfire without the fan in front of the radiator. It has the later 88 relay. Yes, I jumped the red and black/red. The ignition switch was on, the instrument panel was lit up. I did blow the fuse while probing around. But I replaced it.


I've ordered an 88 relay kit from Ecklers. I'll replace the connector, which has very corroded wires/connectors. A friend who has an 86 vette has wired another relay into the circuit that goes to a switch under the dash in case he has a problem. I plan on doing the same. The idea of an adjustable relay from jegs sounds interesting. I see they have a lot of options.

Can someone tell me how to add a jpg to the text?? That’s really cool the way “corvettearchives” added the diagram.
 

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Oh, yea... it's a 84 crossfire without the fan in front of the radiator. It has the later 88 relay. Yes, I jumped the red and black/red. The ignition switch was on, the instrument panel was lit up. I did blow the fuse while probing around. But I replaced it.


I've ordered an 88 relay kit from Ecklers. I'll replace the connector, which has very corroded wires/connectors. A friend who has an 86 vette has wired another relay into the circuit that goes to a switch under the dash in case he has a problem. I plan on doing the same. The idea of an adjustable relay from jegs sounds interesting. I see they have a lot of options.

Can someone tell me how to add a jpg to the text?? That’s really cool the way “corvettearchives” added the diagram.
Hello
On a 84 Corvette the temp sensor between cylinders 1 an 3 is for the cooling fan. All you need to do is ad a switch under the dash that will ground the temp sensor wire,Tee in to the wire leaving it hooked to the sensor, this will ground the relay and turn the fan on, With the switch off the fan will work like stock. Even if you leave the switch on and car is shut down the fan will stop so there's no dead battery if you forget to turn it off. Don't mess with all the high tech temp senders, Half the time they wont come on or turn off when there supposed to.
David Steele
 

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Discussion Starter #10
Fixed but still hot

I received and installed the new 1988 type fan relay. The wire from the temperature switch broke as I was installed the new relay. This might have been the problem to start with. I must have been hanging on with two threads. The fan now works but the car is running a little hot – I think. Going down the highway the temp is around 187 degrees. In stop and go traffic with an outside air temp of 85 degrees, the temp will get up to about 204 to 210 degrees. I’m wondering if the thermostat is too high? The car seems to have a replacement radiator – it’s all metal. The water pump has been replaced. I don’t see it leaking of making funny noises. Any suggestions???
 

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I received and installed the new 1988 type fan relay. The wire from the temperature switch broke as I was installed the new relay. This might have been the problem to start with. I must have been hanging on with two threads. The fan now works but the car is running a little hot – I think. Going down the highway the temp is around 187 degrees. In stop and go traffic with an outside air temp of 85 degrees, the temp will get up to about 204 to 210 degrees. I’m wondering if the thermostat is too high? The car seems to have a replacement radiator – it’s all metal. The water pump has been replaced. I don’t see it leaking of making funny noises. Any suggestions???
I wish my car ran that cool!
 

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Glad its working!

The fan now works but the car is running a little hot – I think. Going down the highway the temp is around 187 degrees. In stop and go traffic with an outside air temp of 85 degrees, the temp will get up to about 204 to 210 degrees.
Totally normal temp. It sounds as if previous owner already installed a newer fan temp switch.
I've had one for 10 years and it works consistantly...on at 205 off at 185.

Odds are it already has a lower thermostat as well. When my 84 had the stock thermostat and fan switch it was up in 225-235 range :ack2:
 

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no thats the sending unit for the gauge

Hello
On a 84 Corvette the temp sensor between cylinders 1 an 3 is for the cooling fan. All you need to do is ad a switch under the dash that will ground the temp sensor wire,Tee in to the wire leaving it hooked to the sensor, this will ground the relay and turn the fan on, With the switch off the fan will work like stock. Even if you leave the switch on and car is shut down the fan will stop so there's no dead battery if you forget to turn it off. Don't mess with all the high tech temp senders, Half the time they wont come on or turn off when there supposed to.
David Steele
On my 84 crossfire between 1-3 is the gauge sending unit , nothing to do with the fans . I think the one your speaking of , is by spark plug 8 !
 
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