I have a 89 350 iroc-z with the stock dual eletric fans. I have noticed that only one of the fans turns on i know that the other fan is not shot since i bridge it one with the other fan to see if it worked and it did. I have been told that the other fan will go on when the A/C is turned on i am unable to test that due to the fact that my A/C dosnt work. Can anyon confirm that this ist true please.

 

I've also noticed that only one fan comes on in my '88. I'm curious also.

 

Dual fans,,,On my car the drivers side fan comes on until 35 Mph then shuts off (ECM Chip) the passenger side fan comes on with the A/C when the temp hits 220 deg. I am using a 180 deg thermostat and on the highway it is 180 deg and in trafic it goes up to 220 which I don't like. Going to try some Royal Purple Ice to lower it.

 

I just found out why my passenger side fan wont turn on and its because the fan switch went bad. From what I hear thats common in these cars. However I made sure the relay was not bad by switching fan relays because both the fans have their own relays and they are the same. They were both okay.

To see if the fan switch is bad.

First ground the ALDL A and B terminals with a paper clip or whatever you use for that. You should hear and see the driver's side fan turn on. If the relay or fan switch was not bad you would see the passenger side fan turn on too.

Second with the A and B terminals still ground take the wire off the fan switch and ground the wire with a jumper wire (MAKE SURE YOU HAVE A GOOD GROUND.) The fan switch is located on the passenger side head in between 6 and 8 exhaust cylinders. When you ground the wire you should see the fan turn on. If it does not you need to check your relay.

If the connector is milted like mine is you can get a new one at yearone.com part number, HC99 or from GM I'm sure is the right one I'm waiting to get my new one and hopefully it will work. If it is not the right one I'll come back here and tell you.