4.slow95

ok everyone knows its hot as ***** and my aux dont work.. i think it worked once. it doesnt come on when its hot as my temp sensor doesnt work. well... its supa broke haha fittin ta go on a jy run in the next couple of days. anyways it doesnt come one when its hot or when i switch the ac. ive tried other aux fans too and same deal. is this all because of the temp sensor or should i just rig it to a switch? and how do i rig it to the ignition. ive heard talks and would like to do such a thing. all help is greatly appreciated. kthx : D

excess650

If you just want to wire in a manual over ride until you get your other issues sorted out, try this.

Find a terminal in the fuse box under the driver's side dash marked pwr acc. Verify that its hot when the ignition is ON, and no voltage is present with the ignition off. I used a 1/4" spade connector and 14ga wire. Run the other end of that wire to the center pole of a switch. Run another wire from one of the outer poles of the switch to the white wire of the fan. You might want to add an inline fuse holder.

Now when the ignition is on, the pwr acc terminal will be hot, and your switch will control whether or not you're sending 12v to the fan.

I'm assuming you can do the wiring, and know how to use a VOM. You might want to check the feed to the fan FIRST and verify that black shows continuity to ground and then turn on the AC and see if you get any voltage to the white wire. If you're getting 12V and the fan isn't running, the fan is toast.

4.slow95

yea wiring is pretty easy most of the time. i just hate the tight spaces...

do you know of anyway to wire it to the ignition so i dont have to find a spot for a switch?

excess650

If you wire straight from pwr acc to the fan, it will be controlled by the ignition switch. The downside is that it will always be on when the ignition is on.

cwabney

Please forgive my newbness, but why is this a downside?

excess650

The fan will turn on as soon as you turn the key, adding power draw while you are trying to start the engine. Likewise, it can't be turned off until the ignition is turned off other than pulling the connector from the fuse box. I think it preferable to have a manual switch and fuse so as to have more control.

djb383

Negative, if it's wired to the ignition/accesory, the fan will turn off (and everything else) when the starter engages.....if it's hot wired to the battery, it's running/pulling power from the battery at the same time the starter is.

cwabney

This is looking like an increasingly appealing option for my XJ... only problem is that I've never wired anything in a car except for a stereo.

I've found an appropriate empty spot in my fuse box, and tested that it gets 12V when the engine is running. Now, how did you wire into that after the test? Did you use the 1/4" spade connecter as a permanent fix? (which would definitely explain the need for an inline fuse holder...) Or is there a more proper way to wire in an auxiliary system to the fuse panel?

Not to advocate this, but we used to fold wire over the end of a live fuse and then jam it back into the fuse box if we needed to draw power for something. Probably a terrible idea, and I'd honestly prefer a more professional wiring solution, if possible.

Lastly, any suggestions for grounding the fan?

freegdr

should just be able to jump the realy

excess650

You can ground to the ground post on the battery, engine block, or body which SHOULD all be tied together anyway.

4.slow95

so basically find the power acc section in my fuse box under the hood put some wire in there along with an inline fuse and ill be straight? which wire should i run to the battery post?

excess650

Find a terminal in the fuse box under the driver's side dash marked pwr acc. Verify that its hot when the ignition is ON, and no voltage is present with the ignition off. I used a 1/4" spade connector and 14ga wire. Run the other end of that wire to the center pole of a switch. Run another wire from one of the outer poles of the switch to the white wire of the fan. You might want to add an inline fuse holder.

Now when the ignition is on, the pwr acc terminal will be hot, and your switch will control whether or not you're sending 12v to the fan.

If you have tested the black wire to your fan and it shows continuity to ground, it won't be necessary to run a seperate ground wire.

Macoozie

Same problem with my 2000.

Turned out my aux Fan was bad. Replaced it.

I had also popped the fuse at #10 behind the kick panel when checking circuits. 15 amp. Check it.

There are great write ups about the A/C system on these last-of-the-breed XJ's. The unique dual nature of the aux fan: to cool the condenser when high side pressure switch exceeds a threshold level OR to come on when the temp switch exceeds a threshhold.
As mentioned by some very sage CF posters, your XJ really should not need the aux fan to cool the radiator. On XJ's without A/C, there ain't no aux fan.

cwabney

Fan turns on immediately when I do this -- regardless of whether the vehicle is running and regardless of whether the AC is on.

Any thoughts? I've started a new thread on the topic here

cwabney

So you're saying the aux fan should turn on when the AC is on AND when the high side pressure switch exceeds its threshold? So it doesn't run all the time when the AC is on?

Could you refer me to some of the write-ups you mentioned? Also, I've started a new thread on the subject.