Cooling fan sensor question/possible problem

[RickIntihar]

I just got my 90 GSX running again, I had to do a coolant crossover tube o-ring, so I did exhaust mani studs, gasket, etc etc while it was all apart.

I put it all back together, and she runs like a champ, but my coolant temp gauge no longer works. I keep hearing people say fan switch and coolant temp switch. and that the fan switch is mounted in the radiator.

The only switch I see on the radiator side of the thermostat is a sensor mounted in the thermostat housing, just after the thermostat. Its a thermistor, and it reads 700Ohms @ 180.9F. This seems out of spec from the specs that I have seen.

There is also another sensor just before the thermostat. I didn't check the resistance of that sensor.

So which sensor is for the gauge, and which one is for the ECU and which one is for the fan itself? I'm afraid the ECU may not be seeing temperature and is still running a warm up enrichment map.

TIA guys!

 

[dsm_Crazed]

There should be three switches total in the system. One is on the bottom of the radiator, and that is the switch that turns the fans on. There are two on the thermostat housing. The one has one yellow wire, and its the switch for the dash gauge. The last has a connector on it with two wires, and its the ECU coolant temp switch.

 

[redyute1]

ok the one with the single wire is for the guage,just un plug it and ground it on the engine then turn the ignition on the guage should go all the way to red,if it does then the sensor is bad if it doesn't then there is a short in the wireing.

 

[RickIntihar]

Thanks guys, I had some corrosion on the single yellow wire terminal under the plastic cover, I just cleaned it up and were good to go.

I checked and the fans come on just as they are supposed to.