cooling fan

[mersco]

one of my cooling fans quit.as you look at the jeep its the one to the left. any suggestions on how to fix?

TIA scot

[Jason Jones]

To the left from inside the cab, or outside?

Is it the electric fan, or the engine fan connected to the engine itself??

If its the one connected to the engine, its probably just the fan clutch, you can get a new one from autozone pretty cheap...

if its the electric fan, you need to determine what broke... could be a few things.. Relay, Fuse, Wiring, diode pack, fan motor. To check the fan motor, just jump power to the fan's connector directly, if it runs, motor is good... on to the wiring. If its all in decent shape, no melts, cuts, rubthroughs etc, its good, move on.. Relay, swap out one of the relays on the relay bank (behind the battery) see if it works, if it does, relay is bad, if it still doesnt, relay is good, move on... Diode pack... I'm not 100% on this thing, Mike R (MJR) has told me about this one, and how it can go bad and cause the fan not to come on. Its probably a relay, its pretty commonplace.

Jason

[Eagle]

We also need to know what year your XJ is, what engine it has, and whether or not it has air conditioning. Would also help to know if it has a trailer tow package, but if you bought it used you might not have that information available.

[mersco]

its an '89 (but its got a '95 engine in it) with 4.0, air conditioning and not too sure bout towing package. and its the electric fan.

[Eagle]

Okay --

The auxiliary fan is activated by turning on the a/c, OR by a temperature switch mounted in the driver's side radiator tank. Test #1 -- find that switch (it's a large hex head located about halfway down the tank, with two wires going to it). Trace the wires back a few inches to the connector plug. Unplug the connector. Try jumping the end that goes back into the wiring harness (with the ignition on, engine not running). If the fan operates, the problem is the switch.

Test #2 -- check the same connector to see which one has 12 volts. Run a jumper directly from the battery to the corresponding terminal in the connector attached to the fam. Jump the other terminal to ground. If the fan doesn't operate, the problem is the fan itself.

[mersco]

it was the switch. thanks. one more question, would that fan not working cause the transmission fluid to get hot and boil over?

[Eagle]

It could. The tranny fluid is routed through the radiator as a cooler. If the radiator overheats, the tranny fluid will also overheat.