We still havn't solved our fan problem..the dealer said that they can pinpoint the problem with their computer check..Here in Canada about $100. bucks just to check it..I guess I'll have to go that route to find out what I already suspect and that is the module is at fault.
I saw an outfit out of Florida that sells refurbished Modules with shipping for around $300..Your lifetime warranty starts when they receive your old one...I'm debating wether to invest the $100..into the module and by pass the dealer check.I really don't think it is in the wiring at this point.

The cruise control on our van also quit working shortly before the fan problem started.
I suspect they are using the cheapest electronic junk they can get their corporate hands on.
Maritime climates are no place for this electronic junk..Fuse boxes or the electronic distribution boxes and busses used to be inside the vehicle which offered some protection from the elements.
In my opinion the desigining engineers must all live in California or Florida certainly some where that is sunny and warm all year long.
I had a new 1988 Dodge 4/4. A beautiful Truck to look at but that is not why I bought it. Had multiple electronic problems with it too..

 

I'm also in the middle of diagnosing a non-running rad fan on this model. I'm NOT a mechanic, but one thing I read says the relay takes information about the VEHICLE SPEED (doesn't turn fan on if vehicle is going down road?).. you mentioned your cruise control problem... could be linked

 

.....

 

Again, I'm not a mechanic, just posting this theory so a qualified mechanic may substantiate or debunk.
From a 2003-2007 Caravan Manual:

"To control operation of the relay, the PCM looks at
inputs from:
-Engine coolant temperature
-A/C pressure transducer
-Ambient temperature from the body controller
-Vehicle speed
-Transmission oil temperature
The PCM uses these inputs to determine when the
fan should operate and at what speed."

Edit: My theory is that the PCM thinks the vehicle is travelling at speed. Possibly linked to the cruise control failure which occured shortly before fan failure.

 

Okay - It finally got warm enough(no snow) to work on my car. I jumped pins 1 &2 with AC on and the fans came on. I looked for voltage that would control the relay on pins 3 & 4 no voltage. Fuse is okay, so I guess it must be one of the other things Knowtian mentioned

 

Fans are now working fine...A young mechanic solved the problem right away...He removed the front driverside tire and inner vinyl liner exposing the computer.
There are colour coded plug ins on the computer.
I don't recall which plug exactly that he pulled out but he did a continuety test on the purple wire in it.
The purple wire runs from the computer thru the Fuse Box I think it is actually called the "Integrated Power Module".
Then goes from the Fuse Box down to the relay.
Relay is located on the frame rail near the driverside headlight behind the Grill.
He cut the wire coming out of the plug and soldered a new piece of wire to it
then run it to the appropriate wire going into the relay..
He cut that wire and soldered the new wire to it.
Bingo......Fans working fine now.
I think the plug in on the computer was the orange one...Not 100% on that though..Hope this helps...