PapPappy

I've got a 1999 Cherokee Sport with the 4.0L six cylinder engine.
I am trying to find a way to help keep it from overheating when I'm driving on the sand. I thought that maybe the electric fan was faulty, but later found out that it's basically just for the A/C, and tied into the compressor switch.
The mechanical (engine driven) fan is used for normal engine cooling.

What I'd like to do, is to install a remote switch in the cab, that I can turn on the fan when I'm in 4x4 on the beach. I'll normally have the fan in it's original configuration, when driving on the road, when the engine temps are normal....but would like the option of extra cooling when I need it.

Any suggestions, as to how I would wire it in. Do I tie the toggle switch into the relay? If so, how?

Thanks in advance.

PapPappy

Any suggestions would be appreciated.

JPXJMOAB

I did it myself, I'll take a few pictures after I get off work. No need for another relay as the circuit already has one and all you're doing is grounding the circuit.

Turbo X_J

When is the last time the cooling system had any maintenance?

PapPappy

I'm not really sure...I just bought this Cherokee. The coolant looks OK, but I realize that doesn't mean a whole lot, and it may have been replaced prior to the sale, just so it would look good, and to hide another problem, but other than the overheating on the beach, the Jeep has been working GREAT.

I also think that part of my problem may be "Operator Error", in that I was in "4H" when I was on the sand, and it may have been overworking the transmission, causing the overheating of the engine, since I was driving at low RPMs, and the engine (mechanical) fan may not have been working as effectively.

Still, I think I'd like the option of operating the electric fan in certain instances like this, which is why I was asking for the help.

Are there any thoughts as to why I shouldn't do it? I understand that it would be additional wear & tear on the electric fan, but I would only use it when driving on the beach, so probably only 5-10% of my driving.

Thanks again :B

Turbo X_J

If the fan clutch is defective and is slipping that can cause high off idle temperatures as well if the radiator is filled with deposits that can cause issues. The "auxiliary" fan is just a cheap, maybe 10% duty cycle fan, which will fail quickly if used for any length of time.

mwxj

For $20 or whatever clutch fans go for now I'd start there as well. And after that work on replacing the coolant related items. I had an override switch in my last jeep but really only used it to shut it off for water crossings never to turn on.

BlueRidgeMark

Read my sig. If you still want the switch, read this.

nardey11

I was thinking of doing this too and I read that it can start throwing codes. Why is that?

PapPappy

I wrote the orginal question, and throwing codes wasn't something I had considered, but it does make some sense, since we would be making some electrical changes to the system, so I would think that maybe there would be some "open circuit" type codes. I don't think it would cause any kind of shut-down code (if there even is one?), since it would be corrected once you switched off the switch?

Am I correct in my assumptions? To the folks who have already done this, have there been any issues like that? I'll be the first to say that the electronics spooks me a bit.

Thanks....

SteveMongr

Driving numerous miles in deep sand is difficult on any vehicle. Requires an auxiliary transmission cooler.
I also use a heavy duty fan clutch and it works well at keeping steady engine temperatures, and the e-fan override switch as backup.

PapPappy

That's a great looking Cherokee. I will check into the Tranny cooler as well as the HD fan clutch.
I'm hoping to work my way to solving this problem in tiny steps, with least expensive at the beginning, so I'm going to go with driving in 4L while on sand, instead of the 4H that I had done last time....from what I've read, this may solve my problems....as the fan clutch may be fine.

Another question to a seasoned "Sand man"....Should I deflate the tires? The information at the beach suggests that I drop the tires to 12-15 psi....but talking with friends, they say that they just drive on their fully inflated tires. I know that the deflated tires are better, but I didn't have any problems with driving in the sand, but then again, I did overheat....so I wondered if that was a factor too? Your thoughts?

Thanks for the help.

BlueRidgeMark

Here ya go.

PapPappy

Thank you sooooo much. I think this will be my next project, as I still have the overheating problem.

I went to the beach again a couple of days ago, and figured I'd try 4L this time, as it was suggested by someone on this forum, that I may have been overtaxing the tranny in 4H.

Now I'm wondering if maybe it's in need of a good radiator flush and tranny cooler (well, extra one).....but I'm trying to do these things in a linear fashion, from cheapest to most expensive, if I can. So far, driving in a lower gear cost me nothing, but I also didn't get a difference.

So, another question might be....I was running with the tires at full pressure, and wonder if lowering the pressure would have made a difference in how hard the transmission works?? I didn't have a problem with traction, and while the sand was "sugar sand" and pretty soft, I was making pretty good headway.

Thanks again for the information on the switch installation!!

BlueRidgeMark

Well, since you mentioned it, check my sig.