RTP fan stays on.

[rgraham]

I have a 1998 RTP that I bought about two weeks ago. It's got 65K on the mileage, and is bone stock.

 

My question is, the fan comes on the moment I turn the key on, and I'm assuming it's staying on the whole time I'm riding. I can't hear it while the bikes running. I rode with a friend today that has an RTP as well, and he says it should only come on if the engine begins to over heat. Makes sense. What should I look for to fix the problem? Thanks.

[BchrisL]

If memory serves me, there is a thermostat switch that is attached to the crankcase that turns it on and off. It may be defective, or it was jumped out. I think it is located somewhere near the oil drain plug.

[11101110]

If the temp switch checks out then the next thing to check is the relay that controls it. and I think the relay is in the nose.

[Woodie]

I know early (pre 97) RTs had the oil temp sensor in the drain plug. Where is it on the later ones? The parts diagrams list it, but don't tell you where it is.

 

[rgraham]

Thanks for the information. I checked out the crankcase and found that there was a sensor on the left side with two wires connected. I pulled each one off individually, and the fan kept running. I don't know if it was the correct sensor or not. I checked the supplementary handbook for RTPs, and found where the fuse was for the fan. I just pulled it to stop the fan. It seemed like it is a dedicated fuse for just the fan, and since RTs don't have the fan anyway, it shouldn't matter.

 

I'd still like to do a proper fix, but for now, I think this should be ok.

 

Is there a way of checking the sensor without taking out of the bike?

[GrumpyOldMan]

Regarding the oil temperature sensor for the oil cooler fan. The contacts in this sensor are in a 'closed' condition when in cold-to-normal oil temperature range (continuity across sensor contacts). When the oil temperature gets hot enough to actuate the sensor, the sensor contacts 'open' (no continuity).

If I recall correctly, the ground for the oil cooler fan relay is through this sensor to ground. In a cold-to-normal temperature range, the fan relay remain actuated (no power to fan). When the sensor actuates (hot), the relay coil ground path is lost and the relay drops out. When the relay drops out, the contacts in the relay 'make' and the fan runs.

Check the contacts across the sensor when the oil is cold-to-normal temperature with an ohmeter. You should have continuity.

If the sensor is good, you most likely have a break in the wire between the relay and ground.

To force the fan on (with the system functioning normally), splice a toggle switch in series with either wire that runs to this sensor. Throw this switch to the 'open' position to force the fan to run.

I don't have a schematic in front of me right now, but I hope this helps.

 

 

[Woodie]

Thanks!