[Chuck]

Its not overheating... its running too cold. I installed a brand new 180 degree thermostat, and still the temp gauge never gets higher than about 160. The engine is running so rich you can smell gas under the hood the next day, obviously the computer is trying to get the motor to warm up.

The thing has 4 electric cooling fans on it, but I don't think that would cause the motor to stay so cold, especially in stop and go traffic.

Anything I should be checking - besides the temp gauge itself?

 

[razman131]

Its not overheating... its running too cold. .........

The thing has 4 electric cooling fans on it, but I don't think that would cause the motor to stay so cold, especially in stop and go traffic.

Anything I should be checking - besides the temp gauge itself?

Holy Crap!!... 4 fans!!? one Viper fan (or equal) is more than enough. I say put the factory T-stat back in and see if that solves the problem.

 

[Chuck]

Yep, 4 fans. Mounted in a 2x2 array behind the radiator. I've never seen anything like it. I think this truck was set up for towing. What it was towing, I have no idea. Theres no sign of fresh or salt water on the frame or pumpkin. In fact, theres no sign of mud, rain, salt, anything. The undercarriage looks like this Dakota just came off the transport. Thats the major reason I took the truck.

I'll probably take a couple of the fans out of the circuit with an in-cab relay and switch.

 

[mopar rt]

It really should not make much difference using four fans. I would check to see when they come on. You should have a thermostat that turns on the fans at a preset temp.

 

[Chuck]

So just follow the wires for the fans back until I find a thermostatically controlled switch? Or is there a standard location for it?

 

[razman131]

So just follow the wires for the fans back until I find a thermostatically controlled switch? Or is there a standard location for it?

ya, with 4 fans is not the factory set up (we only had one fan in 1999). should be some sort of switch. look behind the battery, nice location to put some stuff.

 

[Chuck]

I just got it back from the transmission shop, so I'll check it out tomorrow. After I put the new door lock actuator in. And fix the tonneau cover lock. And order my Hotchkis suspension. This shouldn't be called a truck - it should be called a boat. As in "Break Out Another Thousand".

 

[Laz]

Cooling Fan Control


OK, so I read all the talk about removing the power robbing clutch fan and replacing it with an electric. This sounds like a hot idea, but with my 99, how would I control the fan? I am aware that there needs to be a relay controlled by a thermostatic switch. I also believe it would be a smart idea to have some kind of signal from the AC compressor that turns the fan on when the AC is on. My question is what equipment do I need to accomplish this? Currently, the 99 is pretty much stock in the engine compartment except for a cold air intake. I have the electric fan, but it did not include any kind of control equipment, so I am looking for advice from some of you.

 

[ucimaplaya2]

most thermostatic switches not only turn the fan(s) on and off just by the temp, but they also usually have circuitry for the a/c control, and for a manual switch if you desire one. Check out places like summitracing.com for thermostatic switches like from flex-a-lite, etc. They will usually come with complete wiring guides and if you are familiar with car circuits and relays, then its no big deal.

 

[Chuck]

Here's how it works...

You wire your fan power through the relay, which gets power at the battery + post. The other wire on the fan goes to any ground. Of the other two terminals on the relay, one goes to your keyed +12v power (hot when you have the key on), and the other one goes to a switched ground. The cheap way to do it is to install a rocker or toggle switch to ground the relay or let it hang, but the best way is to put a thermal switch in your intake. When it gets over the specified heat range, it grounds the relay, which kicks the fan on.

If you are interested, I have a 185 degree thermal switch left over from my SPAL kit, and I can provide the wiring diagram with it. The switch is nearly identical in appearance to the factory CTS, just a bigger diameter.

I can get it to you for $25 shipped ground, $35 UPS Next Day air.

 

[Chuck]

I just read the posts above and didn't realize this was from last year! Way to ressurrect a dead thread... :biggthump

I should post a followup to my above question. Now that I've torn my entire motor out and replaced it with something better, I also replaced the stock radiator with a new custom aluminum one, including the SPAL fan kit I mentioned. I discovered that the 4 radiator configuration was definitely someone elses add-on. The thermal control on this one was very bizarre, involving a copper probe stuck through the radiator fins, that went to an adjustable switch box stuck to the frame. Two relays were involved, with the second one turning the system on when the A/C was activated.

I've gotten rid of all that mess and gone to a nice simple single fan now, which should improve my flow through cooling.