First I did search the forums and found this ..

But I wanted to make sure that was what I was looking for. I have a 2000 Dodge Durango 5.9L V8. The electric fan that sits in front of the fan that is turned by the belt never comes on, and if I sit idle to long the temp gauge on the dashboard will slowly climb.

I found the relay in the PCM for the "Rad Fan" and it was scorched and partly melted. I spent the $17 and replaced it. Fan still does not come on. There is power in the PCM slot for the relay, and if I hook power directly up to the fan it runs fine. Some experimenting showed that I could run a wire from the ground in the PCM slot to the ground on the battery and now the fan comes on when ever the ignition is turned on. Truck runs much cooler now, and the A/C is colder.

I assume that the electric fan is normally controlled by a temperature sensor of some kind in the coolant. So if the fan works, but is never coming on, I would think that sensor is probably bad. So the question is... am I on the right track, and if so is the location quoted above the one I am looking for? There is a plug in that spot, but the wire color is different then the wire that leaves the relay in the PCM.

Thanks!

 

I think the OEM Electric fan is only used to supplement cooling for A/C. At least that is the only time my OEM electric fan comes on is when the compressor clutch engages. When my fan clutch went out, the electric fan still never came on even when my temp went over 210.

 

Vydorscope:

Kensai is correct that the electric fan is there to supplement the mechanical fan and it comes on when the A/C is on. So, if you crank on the A/C and it does not activate, there is an issue.

If you are overheating at idle even with A/C off, sounds like your fan clutch should be replaced as well.
How long since your last cooling system flush/refill? Remember the factory green coolant is only good for 3 yrs 36k.

Don

 

I am the only owner of the truck, and I do not recall ever having it flushed. How ever the water pump went out around 100 or 110k (do not recall) and lost all the coolant then. Then a few weeks ago the upper hose on the radiator burst, and in the process of fixing that we discovered that the "new" water pump that Dodge put in was very weak (and looks like the fan looking part of it was rubbing its casing), so replaced that with a new one from Advanced Auto Parts ( ASC Water Pump) . When that happened we had to add three gallons of coolant.

The A/C runs very well right now (with the relay grounded as described above), so would that still mean it could be the clutch? The A/C worked okay-ish before we ran that ground, but not as cold. If it is the clutch is that hard to change? Where is it?

As I mentioned above, the fan will not come on no matter what if we remove the ground we ran. The truck has gotten well past the 210 line on the gauge, most of the way to the 265 line, while sitting idle with A/C on with no fan action.

 

Sounds like a mechanical fan clutch failure then. when my temp started hovering 210 and above, I had mine checked and noticed the fan clutch is dead. the fan was turning but not enough to pull air and the efan is not pulling enough air to keep cool. Heck, I can even hold the fan blades when the engine is running just to show the clutch is totally broken! Since I got it replaced with a new one, I been running cool ever since. Even my A/C has improved alot.

 

Well.. it not turning at all with out my jump wire, so its not weakly working like you describe. When we tested fan's power plug it never gets power, which is why I was assuming it was the tempature switch. Where is the fan clutch so I can check it out and see if there anything obvious wrong?

 

The fan clutch is the belt driven fan. It is the aluminum looking thing attached to the front side of the fan. Just pull the fan blade off (all you need is a strap wrench and a large wrench) and it will come out with the fan. Bolt a new fan clkutch on and you're good to go. It is a 30 minute job tops.

 

Ah, thanks. Well then it seems it would be unlrealted to my problem with the eletric fan.

 

Could very well be and fan clutches like to go out on these D's it seems. If you have time on your hands you may want to look at the viper fan thread here at the top. I am looking into one of these lincoln fans today, it's cheaper than a fan clutch and will free up a lot of power.

 

If you get the fan clutch replaced, just be prepared to hear a loud fan roar indicating the clutch is doing is job! haha. Already someone posted a thread about the fan clutch being noisy! haha