ARRGHHHHHH! I hate electric fan thermostats!

[asphaltrockdweller]

I was running up the I5 today, and all of the sudden my temp starts creeping up again

So I pull off the stop start traffic, and NO FAN! Again!

This is the second time in two years a Derale fan thermostat has headed south on me.
So I got out the wire strippers, and hooked up the fan directly to the battery till I could get to a parts store. (temperature started heading left on the gauge right away too)

Ended up just buying a 40A Bosch type relay, 10G & 16G wire, and some crimp connectors.
Taped into one of the splice K wires for power "ON" to the relay, and then just wired straight to the battery, and fan.
Honestly I am contemplating just leaving something like this in line, and pitching these darn thermostats?
Maybe add an OFF switch to it, you know so if I ever do water or mud crossings maybe?

[robert_hollis]

I run my electric fan with a 40A relay, and an On/Off switch. No thermostat, or relay plug-in (I had the old plug-in go south).

I just watch the temp gauge when I start up, and turn on the fan when it gets to a temp I like.

We should all watch our temp gauge enough to not 'forget' to turn the fan on, so I see nothing wrong with this. It's not like I loan my Cherokee out to anyone...

[jeepfan93]

You want your controller broke on the ground side. So you wire up the hot's to your relay as normal. The ground for the relay, should go through the probe you are using. This takes the stress off probe. I've been running mine for 6 years on the Jeep, and 2 years on my f150

[chrism]

Go to a regular thermo switch. Here is a link where you can search Wells sensor catalog for one that fits your application.

http://www.wellsve.com/custom_searches/ds_fans.php?showall=yes

I have been using SW510 (on at 210 and off at 185) in my CJ for 12 years now. The Borg Warner part number is for the same part is TFS12P.

[djongeward]

I'm currently running the fans on switches only, mounted in the wags overhead garage door opener bay. I have several temp controlers I want to wire in, wiring them to keep the system on if they go down is a good idea. I've always ran them manually from the cab via relays and yes, you can forget to turn them on and off, get distracted, etc. I would rather have them automatic with me as backup then the other way around.

Somewhere in the mix I want an idiot light to assure on or off when on auto mode.

At least I have a real good idea where the fan temp settings need to be.

[Blake]

I still don't understand why folks mess with electric fans - too much trouble and a bad point of failure.

the stock amc cooling system works fine - when it's all there and in good working order.

[asphaltrockdweller]

Blake I am starting to conceede to you.

My 74 waggy has a stock cooling system, and it works just fine.
I am just about to take that pretty BJ's radiator & fan out of the 76 360 wag, and just go all stock.

[Mountain Dude]

I am running a Delta Current Controls 2 speed controller and ford Taurus fan in my TJ, works excellent.

Just checked and their website is down for "maintenance", here it is anyway:

http://www.dccontrol.com/

[BGW]

I still don't understand why folks mess with electric fans - too much trouble and a bad point of failure.

the stock amc cooling system works fine - when it's all there and in good working order.

X2. With a good fan clutch, the stock fan moves a much higher volume of air than any electric I've seen so far. Also, you don't have to worry about taxing the electrical system.

It is nice to be able to turn off the cooling fan when crossing rivers though. I've always wondered if the electric fan clutches found on Ford Superduty trucks and the like could be modified to fit on an FSJ. I think that would be the best of both worlds.

[djongeward]

I still don't understand why folks mess with electric fans - too much trouble and a bad point of failure.

the stock amc cooling system works fine - when it's all there and in good working order.

Well they just don't, when in low rpm conditions off road in high ambient desert temps. My BJ's system will keep me at 190 all day at low speeds, AC running, and 115 degrees. It dosen't work as well for me at high speeds. Trade off? Perhaps!

[Rich88]

Well they just don't, when in low rpm conditions off road in high ambient desert temps. My BJ's system will keep me at 190 all day at low speeds, AC running, and 115 degrees. It dosen't work as well for me at high speeds. Trade off? Perhaps!

During the 80's I ran a 76 Cherokee completely stock in 100+* heat many times, (helping to re-open the Old Mojave Road between Needles and Barstow) and never blew steam. Included running up sand washes and rock crawling. Come to think of it, I don't recall any of my associate desert rats with FSJs, CJs and LCs had anything but stock either.

I think the majority of cooling issues are guys buying worn out FSJs, discovering a cooling problem, and instead of replacing radiators, water pumps and fan clutches with new ones, think they have to cure the problem with after-market schemes and gizmos.

[asphaltrockdweller]

I think the majority of cooling issues are guys buying worn out FSJs, discovering a cooling problem, and instead of replacing radiators, water pumps and fan clutches with new ones, think they have to cure the problem with after-market schemes and gizmos.

No truer words were ever spoken!

Amen & Amen!

When I bought my poor old wagon it was overheatin sumfin awfoul!

I did not know just exactly how tired it really was.

Then I started hearing about this shinny aluminium crossflow radiators, and electric fan kits, and just how nifty cool they kept things.
So I did all the really nifty cooling stuff, when I """Rebuilt the engine"" Thinking it would be all the answers to what ails me in hot weather. You know flowcooler water pump, BJ's radiator, and electric fan kit, 195* Robert Shaw thermostat.
I thought I did all of the right things?

Well my stock 1974 waggy sure runs cooler than my fresh 360 in my 76.
I will be changing back to a stock radiator, fan, and fan clutch very soon I can tell you that.

Of course YMMV?

[robert_hollis]

This thread has become one of those dead horse debates I just love to read.

Can we start arguing about auto vs manual trannies next?

[serehill]

It certainly is

This thread has become one of those dead horse debates I just love to read.

Can we start arguing about auto vs manual trannies next?

Simple analysis the t-stat contol isn't heavy enough. Why do some work & some don't My sons 96 mustang has been in the family since new it has 180K on it with the original equipment. I built my own. It's a contact style t-stat & w 50 amp relay. The same relay that is on the f-350. Engineering wire size proper current are key survival requirments one of those has an issue. Cost me 22 bucks. My 225 amp alternator gizmo has no problem with current.

Nostalga: Anyone remember rush hour traffic back in the 60's & 70's all the cars that would overheat in rush hour traffic? Steam pouring out from under them dead blocking traffic in the middle of the road. Where did they go?? I'm not saying it doesn't happen at all anymore but in Dallas in august there were tons of them.


Electric fans. Well let's see How many new vehicles have electrical & how many have mechanical?
When in rush hour traffic there's NO way a mechanical fan will move as much air. The very biggest problem with mechanical fans they work the least when you need them the most.
Off road you can turn the fan (if you build in that option) off to keep it from drowning your engine when needed. This can even be an advantage in a torrentail rainfall.
Overheating reduced & a.c perfomance is improved. over fanning & utilizing it for towing in the middle of the destert or just on 160 degree asphalt in Texas are all good reasons for electrical fans.
Having a transmission cooler in front of your radiator to block more air is another reason..
Better gas milage even though it's slight.
You can put a push & pull unit on so in the event of one failing the other will get you home. Probably not important unless you're 20 miles from the nearest road.
Another point that has been made is very correct. Both systems on average will work. Some people put electrical fans on to fix a problem that is being created from a bad cooling system issue. Both depend on a good system.
Electrical systems are anemic on the rigs they should be improve. If an electric fan over taxes your system then it's to small anyway. The smallest of cars built today have larger charging systems than the FSJ. The proof in tons of threads on this site.

My vehicle I suppose is a plethora of after market schemes & gizmos that happen to be on most late model vehicles. It works great. I'm running both electric & Mechanical. One of these days the mechanical will go away.

The dead horse when utilized to seperate your needs from others is a functional process.
The automobile manufacturing & trucking industy Have deemed the mechanical fan a dead horse. They have spent millions on the subject.
However most follow this process.
The tribal wisdom of the Dakota Indians, passed on from one generation to the next, says that when you discover that you are riding a dead horse, the best strategy is to dismount.



But in modern business (and education and government) because heavy investment factors are taken into consideration, other strategies are often tried with dead horses, including the following:



1. Buying a stronger whip.

2. Changing riders.

3. Threatening the horse with termination.

4. Appointing a committee to study the horse.

5. Arranging to visit other sites to see how they ride dead horses.

6. Lowering the standards so that dead horses can be included.

7. Reclassifying the dead horse as "living-impaired."

8. Hiring outside contractors to ride the dead horse.

9. Harnessing several dead horses together to increase speed.

10. Providing additional funding and/or training to increase the dead horse's performance.

11. Doing a productivity study to see if lighter riders would improve the dead horse's performance.

12. Declaring that the dead horse carries lower overhead and therefore contributes more to the bottom line than some other horses.

13. Rewriting the expected performance requirements for all horses.



And, as a final strategy:



14. Promoting the dead horse to a supervisory position.

[Skeeter74]

Now that is FUNNY!