1988 XJ OEM fan switch

Is there one or two? There is one in the radiator; a rather large plug with an aluminum washer and there is another in the engine block above the engine mount bracket, that fit into a 3/8 pipe; or is it? I has a two wire connector similar to to one in the radiator. Are they both on/off switches or variable resistor/switch and at temputure do they switch between on and off? TIA.

The one in the radiator is a temp switch to determine when the electric fan turns on and off.

The one in the block should be a temp sender for the water temp gauge. I have not looked for it and am not positive this is where it is on the xj. But this is what I would assume, can some one verify this is where the temp sender is for the gauge?

Michael

88 XJ the one in the radiator is for the aux fan. The one in the block sends data to the ECU. The one for the gauge is in the back corner of the head.

The temperature sensor for the gauge in the dashboard is located on top of the engine block, next to the firewall, on the drivers side. Single wire. (at least on my 87' is that way.) It does not matter if you have the gauge or just an "idiot" light, there in the same spot. Hope this helps...

Ummm, Jay ... that's not the block, that's the head.

Thanks guys. Question, at what temperature does the fan turn on and off?

The fan should turn on when the switch reaches around 180*... now, remember, it is on the outlet side, which is the cool side of the radiator, so to test it, you have to cover the radiator with cardbord and get the outlet of the radiator up to temp.
watch your engine temp, it should reach about 210 before the electric fan kicks on....dont let it get too hot. you can watch your thermal fan cluch at the same time to see if it is working properly

Also, make sure the heater switches are all off as the electric fan will cycle with the a/c when its in defroster mode.

Eagle said:

Ummm, Jay ... that's not the block, that's the head.

Click to expand...

Thanks for the correction. Oops...