Overide fan switch for 2000 XJ?

Hey guys,
the search isn't turning up what I need, so I'm asking-

Anyone got specific instructions on how to wire a fan switch so I can run my e-fan on my 2000 XJ?

I'm a suspension guy- they don't let me mess with the electrical much...:dunno:

I think I'd like the factory settings to still work, but add a switch that would allow me to override that and force the fan to stay on.

Also, I'm thinking I'd like it to shut off if the ignition is shut off, so I don't mess up and leave the fan running to rum my battery down.

Thanks!

Dirk

You can add a relay into the turn-on line to the relay coming from the computer. The relay is needed for the computer to not throw a CEL and still be able to turn on the fan. The switch inside will just ground the main relay. There is an electrical diagram, search for the original FitchBox thread, I think it's in there.

EDIT: On the 2000 model that I know of, the positive side of the fan relay is ignition switched so everything will turn off when the ignition is off.

No need for relays, even simpler. I just did this a few days ago on my 2001 and I am no electrical genius at all. Pop the hood, drivers side of engine bay will be a few wiring harness right inside the fender. Start digging in the biggest wire harness for a blue w/ PINK stripe wire. Be careful! There also a blue w/ red stripe, blue w/ Orange stripe and I have no idea whay they do. Clean wire insulation off mid wire somewhere and solder another wire of similar gauge off it. Run that wire to one side of a switch.

Now take another wire of similar gauge and and run it off the (-) battery terminal. Run that wire to the other side of switch. Done. Will only run with the ignition in the ON position or running. It will not work on accescory either. I have no CEL yet and I think I read somewhere that if you ground it to the battery instead of just a random spot on the body it will not throw a CEL. Don't quote me on that though...

Sounds good so far, but maybe some corroboration on this?

I like simple too, but I caused my guys close to 100 man hours tracking down a wiring meltdown after I installed some add-on back-up lights to my TJ a few years back. That's why I'm not allowed around the electrical stuff...:shhh:

Who all has done this?

Thanks!

One way to go:


Works...

Probably best to add the relay.

o-gauge-steamer said:

One way to go:

Works...

Click to expand...

Worked for me also. Great mod.

I've done the override switch without the relay. Works great, but trips the CEL every time. Putting in the relay is on my to-do list.

All connections are made at the fan pigtail, if you don't want to mess with the PCM wiring. Works perfectly, no CEL.

Yep, many follow this thread with pictures written by fyrfyt1717 !!

http://www.naxja.org/forum/showthread.php?t=1025399

Good luck Dirk. BTW, I still enjoy my 4 inch OME/DPG Hybrid lift!!

would you explain pin 86 a little better?

I really want to do this, but electrical is not my strong area like the OP.

Pin 86 on Bosch type relays powers the coil which creates a magnetic field completing the circuit between pin 87 and 30, effectively powering the accessory on.

I need to redo that drawing so it's a little easier to read.

Wired it up right from the PDC with a lighted switch and no relay.

Works perfectly and no CEL. We were a bit concerned that the switch light might pull enough voltage from the circuit to throw a CEL, so we wired a non-lighted switch in. THAT threw the CEL, so we went back to the lighted switch and it works fine.

I'll go with the relay and all if I have any more troubles...