1988 XJ, Limited, 4.0L electric fan question

[Don Becker]

Hi, all! I've been off of here for awhile but I still have my '88 and the wife's 91 XJ's.

I have actually spent quite a bit of time searching on here, in the archives, for the answer to my specific problem, without success.

I do not currently have a cooling system problem - - well, at least not overheating. This is (as noted in the subject line) re the '88 and the cooling system is fully retained as original, closed system.

The electric fan comes on and operates just as it should when the a/c or the defroster is in operation.

Always before, (with a/c or defroster off) that electric fan would cycle on and off as the temperature got to the 190 degree range - - especially at idle. Now, it doesn't come on at all.

See diagram (I hope it will attach here):

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I have been through all of the checklist but, at item 7, I do not have battery voltage at terminal 2.

I think that is controlled by another fusible link but, I don't know for sure and if it is, I don't know where that fusible link is.

Or, if that voltage is actually supplied when the switch in the radiator is on, I might have a problem with the sensor/switch in the radiator - - I know that switch is in its ordinary open position - - - what I'm unsure of and will maybe need to test further is whether that sensor/switch is actually closing when the temperature rises.

Thanks for your assistance with this.

Don

 

[jneary]

does the fan operate if you jump the wires at the temp sensor in the radiator? there is a relay on the left side inner fender. there should be one or two there and one on the core support. i cant remember which is for what, one is cooling fan and one is fog lights if equipped. if you jump the switch and it still doesnt work it maybe a relay or corrosion in the relay or connector

 

[Don Becker]

I'm not certain whether that diagram is showing-up for you or not. When I look, sometimes it's there and then sometimes it's the dreaded box with the red X. Anyway, "no" the electric fan does not run when jumping the plug that attaches to the radiator sensor/switch. I have identified the correct sensor/relay and it's that number 2 terminal that seemingly is supposed to always have battery voltage - - that leads me to think it is not the relay itself. That's probably not making much sense if you are not able to see the attached diagram. I'll see if I can figure-out how to attach it better. Don