darkhorse91

My 91 RS overheated and my research led me to believe that it is the fan switch in the passenger side of the radiator. When I looked it appeared that the switch has been disconnected, and the wiring discarded. Any help would be greatly appreciated.

Danno

There is no fan switch in the radiator. If you have what appears to be a lug with no connection it is not used. GM supplied some production and replacement radiators that had the low coolant level probe. In models without a low coolant indicator light it was simply not used. The fan switch is located on the passenger side of the block near cylinders 6&8. Try replacing the fan control relay, it is a very common reason for intermittent overheating. If you have A/C turn it on, if the fan relay is OK the fan should run. You can also pull the wire off the fan switch and ground it with the key on engine off and the fan should run if the relay is OK. Replace the relay first, it is not expensive and a lot easier to change than the fan switch. Otherwise use normal cooling system troubleshooting as described here on the site or from any service manual.