Radiator Fan help please

[goddom]

The fan doesn't work. I hooked up some power to it and the fan it's self works so there is a problem with the electrical some where. I only have a Chilton's, which as you know is crap, so I am not sure where the fan relay might be or if there is a switch in the block, or anything else that I might need to know. There is a relay mounted on the fan shroud which is what I am guessing is the fan relay. If so then how would I test it or the connnector with a multi-meter since it looks kind of corroded.

Thanks,
Matt

[veedubmechanic]

If it looks corroded then you need to clean it off real good. COrrosion on connectors causes high resistance whice causes electrical components not to work. Get some good electrical parts cleaner or battery terminal cleaner and clean it off first and see if it fixes the problem. After cleaning it put on some dialectric grease on the connector points to help prevent corrosion.

[boschmann]

There's a low speed relay under the dash, a high speed relay at the fan shroud & the thermoswitch in the radiator. If you jumper the switch to high it should run the fan, otherwise the fuse link is bad.

[goddom]

How do I switch it to high and which relay under the dash is the fan one?

[boschmann]

To run the fan on high jumper the radiator thermoswitch harness connector red wire to brown/white (or brown/yellow) wire. To run the fan on low jumper the same connector red to grey/black. The low fan relay is position #1 (top left) aka a/c relay.

[goddom]

one more question; where is the thermoswitch located? I was looking around for it but it was hard to find.

Thanks

[boschmann]

About midway down the left radiator tank on the engine compartment side.

[goddom]

I jumped the wires like you said and the fan came on. So I figured the thermoswitch was bad and replaced it, but it didn't seem to fix it. Perhaps the thermoswitch I got was bad?

[boschmann]

With the jumper both the low & high speeds worked? It's possible the radiator isn't getting hot enough to activate the switch. Perhaps the thermostat is stuck or the radiator isn't flowing properly.

[pissboy]

does it run hot or cold?
if it is over heating than your t-stat is stuck closed.
if its running cooler than normal than your t-stat is stuck open.
the new sensor you got is probably good not to many new ones are bad out of the box. how many wires go to it? 2 or 3? you can check it with an ohm meter. when its cold it should be open and if you put the sensor in warm water it should close.

[goddom]

It has three wires. Which wires should I test with the ohm meter? I don't know what hot is on the temp gauge, the gauge sits about in the middle and the oil temp is about 180 degress when the car is warmed up. I got the car a couple of weeks ago.

Thanks

[pissboy]

one of the wires probably the closest to the middle is your common, put one lead on that one then test the other leads going to the sensor.
if you get a reading on one and not the other stick it in some hot water and do it again. if it is the opposet wire then it is working. you might have to try a couple of different combos till you get it right. sorry I can't tell you exactly which wires. are you sure the fan doesn't work it doesn't run all the time. my old jetta and my new GTI both run around 190 water temp. test it could be the sensor.

[goddom]

Thanks, I will give it a try. I did try and test the old one with a lighter when I took it out of the radiator. There were no changes when I had the lighter on it for a while and when it was cold, so I am sure the old one was bad.