Hi guys,
I have a 2004 Dodge Dakota xtra cab, four wheel drive with the 4.7 liter motor.
This truck has been amazing. I have plowed with it since it was brand new. I have tried very hard to keep the truck maintained and in good shape. The truck has 160,000 miles and it doesn't burn any oil. I have been using synthetic oil since 3,000 miles (Amsmoil). Because I live in the northeast and because of the product they throw on the road, I have had to replace the oil pan, transmission pan and brake lines. In the long run I think this has helped the truck.
Now to my problem. I think all these problems are related that is why I am mentioning them altogether.


The air conditioning has always worked great. Last year it stopped working. My mechanic pressure tested it and put a dye in the Freon and could not find a leak. I have yet to find out what the problem is with the a/c.
I have never had an issue with the truck over heating even with the plow on it. In addition to having the plow loaded on it, I have a sander that fits in the tow hitch frame and I carry several bags of sand in the bed to put in the sander when the sander runs out. I am very careful with the truck when I am loaded this way. But like I said, I have never had an overheating problem until this year.
I took the truck to my mechanic and he said that the clutch fan seems to be fine but he can't tell if the electric fan is working or not. I was discouraged by his lack of effort in locating the problem. I took the truck to a Dodge dealership and they said that both fans needed to be replaced along with a oil pressure switch at a cost of $950. The other mechanic specifically said that the clutch fan was fine because there was no "slop" and it seemed to work fine. I was not happy with the fact that they were just eliminating both possibilities by replacing both parts. Oh, and by the way, the other mechanic replaced upper and lower hoses and the thermostat.
I started to do some research myself and found that many guys replace both fans with one electric fan. For two reasons, the clutch fan draws horsepower and the one bigger electric fan works great (according to what I have read on the internet so far.
So, I am looking for opinions. If I do replace both fans with an electric fan, what fan should I buy? They look easy enough to install.
Thank you in advance so much for your help.

 

Welcome to DF!

Since you have a plow on the front, get the biggest fan that will physically fit, and has the highest flow rating.

What does your coolant look like?

Does your A/C actually lose refrigerant? Might be the evap core leaking. (in the dash....)

 

When I had the air conditioner problem at the beginning of the summer, my mechanic replaced the top hose that has the radiator cap and replaced the coolant. The hose the cap is on was leaking so we figured we start there.

 

Welcome to DF. Moving to the correct technical section.

 

Welcome to the forum.

A leaking radiator hose won't stop the a/c from working. He did hook up a gauge set? Do you know the readings?

It shouldn't contribute to the overheating problem either.

On the clutch fan, if you are getting hot it should engage - period. You'll hear it roar when the engine is hot and sometimes when first starting. The electric fan is supposed to come on when you start getting hot, around 210 or so, or cycles with the a/c.

Here's how to diagnose the clutch fan:

DIAGNOSIS AND TESTING—VISCOUS FAN DRIVE
If the fan assembly free-wheels without drag (the fan blades will revolve more than five turns when spun by hand), replace the fan drive. This spin test must be performed when the engine is cool.

For the following test, the cooling system must be in good condition. It also will ensure against excessively high coolant temperature.
WARNING: BE SURE THAT THERE IS ADEQUATE FAN BLADE CLEARANCE BEFORE DRILLING.
(1) Drill a 3.18-mm (1/8-in) diameter hole in the top center of the fan shroud.
(2) Obtain a dial thermometer with an 8 inch stem (or equivalent). It should have a range of -18° to 105°C (0° to 220° F). Insert thermometer through the hole in the shroud. Be sure that there is adequate clearance from the fan blades.
(3) Connect a tachometer and an engine ignition timing light (timing light is to be used as a strobe light).
(4) Block the air flow through the radiator. Secure a sheet of plastic in front of the radiator (or air conditioner condenser). Use tape at the top to secure the plastic and be sure that the air flow is blocked.
(5) Be sure that the air conditioner (if equipped) is turned off.
WARNING: USE EXTREME CAUTION WHEN THE ENGINE IS OPERATING. DO NOT STAND IN A DIRECT LINE WITH THE FAN. DO NOT PUT YOUR HANDS NEAR THE PULLEYS, BELTS OR FAN. DO NOT WEAR LOOSE CLOTHING.
(6) Start the engine and operate at 2400 rpm. Within ten minutes the air temperature (indicated on the dial thermometer) should be up to 88° C (190° F).
Fan drive engagement should have started to occur at between 74° to 82° C (165° to 180° F). Engagement is distinguishable by a definite increase in fan flow noise (roaring). The timing light also will indicate an increase in the speed of the fan.
(7) When the air temperature reaches 88° C (190° F), remove the plastic sheet. Fan drive disengagement should have started to occur at between 57° to 79° C (135° to 175° F). A definite decrease of fan flow noise (roaring) should be noticed. If not, replace the defective viscous fan drive unit.

 

If the freon is not leaking, check to make sure the compressor is engaging properly. If the compressor clutch is working, the compressor itself might be bad.

 

As usual, Dan is first in, follow what he says. IMO, if the clutch fan works, keep it. If not, get one from the junkyard. Any dodge Durango, Dakota, or ram will work I believe.

Pull the electric fan, and put a Lincoln mark 8 fan on it. You'll have to fabricate 2 brackets, one for each side. You'll also have to cut and grind the upper corners of the shroud to clear the coolant tanks. I have multiple pictures of my setup on the forum.

I run the mark 8 fan only, but when the motor burned out, I didn't realize it, and got in the 240's. Having the clutch fan will be a good backup, and add any extra cooling you will need.

You can cut the pigtail and splice directly to the mark 8 fan, or do like I did, and use the stock pigtail to power the coil of a high power relay, and run 10 gauge from the relay to the fan. Then you can tap the coil to a dash switch, and turn the fan on whenever you want, and it will still come on at 210 or with AC.

 

Thank you very much. Really appreciate it.


My question is, you mention using the clutch fan as a back up, do you mean leave the clutch fan in place? Or remove it and have it "in stock" as a backup?


You mention using a Mach 5 fan, are you intending me to go to a junkyard? One of the things my mechanic said that made sense buying a used electric fan was probably not a good ideas, but on the other hand if it is only working when the engine reaches a certain temperature, than why not?


In addition, would this electric fan problem have anything to do with my a/c?

 

For what you do, I would leave the clutch fan on. I kept mine when no did the swap, just kept it at the house. Problem was, e fan failed (brushes wore out, sealed motor) at school. I towed home and put clutch fan on and ordered a new fan motor. I went for performance, you need cooling. I suggest using both.

The mark 8 can be from rockauto or the junkyard. I got mine from the junkyard and it lasted a year and a half before motor went out, I got it for $55. I forget what the replacement motor was. Well worth it IMO.

 

https://dodgeforum.com/forum/2nd-gen...n-convert.html

https://dodgeforum.com/forum/2nd-gen...at-hurt-4.html

Here are my threads with pics