Question: Electric.fan on 84 vette

[donnie reynolds]

I recently became the owner of a 84 crossfire corvette. It had an assortment of things to be corrected.I,m now having a problem with the electric fan,at first it would stay off until 200-212 degrees then come on, then it would go off an not come back on at all, now its on as soon as the key is turned on.Being not familar with this system should I replace the relay or the fan temp sender. The high temperature the car normally runs at has me loosing sleep anyway. Any advice would be greatly appreciated.:

 

[ex-x-fire]

The cooling fan is turned on by either the the sensor in the pass. side head(between 6 & 8 cyl), or the a/c being turned on (only if the a/c has a charge). Does the a/c work? Check the sensor & the wiring (as it is near the exhaust manifold). When that sensor closes it grounds the relay which allows the relay to send power to the fan.

 

[vetteoz]

 

[BADDUCK]

I recently became the owner of a 84 crossfire corvette. It had an assortment of things to be corrected.I,m now having a problem with the electric fan,at first it would stay off until 200-212 degrees then come on, then it would go off an not come back on at all, now its on as soon as the key is turned on.Being not familar with this system should I replace the relay or the fan temp sender. The high temperature the car normally runs at has me loosing sleep anyway. Any advice would be greatly appreciated.:

It could be a problem with the relay or sensor/switch. You can go to a lower temp. sensor if you want. however, don't go too low the fan will run all the time.

 

[Hot Rod Roy]

This is a pretty common problem with the early C4's. The connector and the relay are weak links. The connector for the relay has small contacts, like "spade" connectors, that overheat and become weak with age. The best answer is a larger capacity relay, such as 50 amps, which have larger contacts. It takes some rewiring to get rid of the weak connector, but it's a permanent fix! Don't forget to add the diode, as shown in the diagram posted earlier. A 1N4002 or equivalent is good.

P.S. the relay is located on the left fenderwell, near the front of the master cylinder.

 

[mike]

electric fan on 84 vette

I had the same problem with my 84 vette. I replaced the relay, and the temp. switch, and still had the problem. I replaced the high pressure switch on the airconditioning and that solved the problem. As far as the engine temp, it does run higher on this car, my fan will come on at 235 and go off at 210 if the car is idling. when driving down the road at above 40 mph it never gets above 180-190.

 

[donnie reynolds]

This is a pretty common problem with the early C4's. The connector and the relay are weak links. The connector for the relay has small contacts, like "spade" connectors, that overheat and become weak with age. The best answer is a larger capacity relay, such as 50 amps, which have larger contacts. It takes some rewiring to get rid of the weak connector, but it's a permanent fix! Don't forget to add the diode, as shown in the diagram posted earlier. A 1N4002 or equivalent is good.

P.S. the relay is located on the left fenderwell, near the front of the master cylinder.

Thanks Roy,I'll try changing the connector. I did add a manual switch but the fan started running all the time.

 

[Hot Rod Roy]

Thanks Roy, I'll try changing the connector.

Does your relay connector have heat damaged terminals on the red wires? That size terminal is usually rated for about 15 amps. Your fan pulls more than 15 amps, so you'll have a short life for those terminals. I installed a 50 amp relay in my '84, which has larger terminals.