Can anyone tell me where the radiator fan RELAY is on a 1987 s80 550? My fan runs all the time and the radiator temp sensor plug is undone so I know its not the sensor. I'm guessing the fan relay has fused contacts or wiring is shorted but can't find anything unusual. If I could just find the actual relay,if there is an actual relay,I could check it out. Thank you in advance! tom
s80 radiator fan on all the time I figured out why my fan was on all the time and I could never find a relay for it. There is NO relay for the radiator fan it is all done in the temp sensor in the radiator itself. The temp sensor is strong enough to carry the fan load by itself, I found where a previous owner had put a wire splicer across two wires near the sensor and shorted the wires causing the fan to run all the time. I removed it and now all is well, maybe this will help someone. tom
that seems like a lot of load for a fan thermo switch??...make sure the temp switch is working..they are a bugger to find a replacement as the threads are a 3/8GAS (tapered pipe threads).....haven't had a chance to get under mine lately and check for you...glad you got it worked out
Thermal sensor is working fine and is tested, I varied the load by shorting the sensor leads and the fan sped up and down accordingly so I know there is no relay. tom
You have a radiator thermo control switch on your vehicle. It’s the sensor looking item on the bottom left of the radiator (passenger side). When it’s shorted it defaults to “ON” position running the fan constantly not to overheat the engine whilst driving. Left in this condition it will burn out the fan motor. Cheers, Don
