Cooling Fan and air conditioning switch

[Richard and Cris]

Can anyone explain what is needed to fix an '04 Alpine 400hp cooling fan to come on when Air Conditioning is turned on?

[EngineerMike]

Did it come on before?
There is a Saur-Danfoss fan controller gizmo (could be mounted on the frame just ahead of the fan motor, or could be somewhere else) about 4" square by 3/4" thick and screwed to a valve body about the same size. It should have a series of wires to it, one of which is the demand for fan for AC-On. If that is receiving signal but the fan is not coming on, you need a new controller. It should have a # on it, and a new one can be ordered through John Lamb, Berendson Fluid Power, (509) 536-5995.

[Old Scout]

There is a long thread [use search option] to review this item on the forum. Appears 2003 and earlier [our 03] have a mechanical switch [wax valve] that ties the engine temp and the fan activation together--this arrangement ignores the AC's need for cooling. Some time after 03, an electrical switch was used. Perhaps a fellow 04 owner can tell you for sure--with all due respect EM....

[EngineerMike]

No respect required.
If anybody knows where the fan controller is on an 08 rig w/the smog engine (i.e. MY rig) please let me know. I've searched hi & lo for it to no avail.
Even I'm losing respect for me.

I was under an 04 two weeks ago and located the S-D controller as posted above. Doesn't mean all 04's work like that or have the controller located there.

[Richard and Cris]

My '04 has what looks like an thermostat control in the back of the radiator with the hydraulic line running through it to the fan. My engine is the last of the pre-smog breed. I thought someone might be familiar with the kit some have used to allow fan to come on with air conditioning.

[Jim&MaryJo]

My 04 had an AC system failure due to this problem.
http://www.irv2.com/forums/f104/04-d...ice-26777.html

At the time, WRV provided me with a kit comprising a hydraulic valve and solenoid. The solenoid tapped into compressor wiring and the valve was installed midstream to the hydraulic fan.

I don't think the shop who installed it is still in business. If I can find them, I'll post for a technical contact.

But, I got the impression that they thought it was a simple fix and had seen this problem on other coaches. And, the kit parts appeared to pretty common and could be sourced elsewhere.

I'd suggest calling some RV shops with this explanation to see if they're familiar and can source the parts.

[Old Scout]

Check out the threads on this form--I installed the upgrade kit on my 03 a couple years ago and it has worked well. Parts are common thru places like Grainger but our ACA tech Mark H. has the contact thru a shop in Yakima that "built" the original kits for WRV....

[gator67]

Recently the compressor came on in our rear A/C but not the fan. Someone else had the same problem and they said their "squirrel cage" was stuck. He suggested I take the cover off the unit on the roof, spin the fan a couple of times and that should take care of the problem. That worked for me... hopefully, your situation is just as simple.

[takepride]

??? (Sorry, couldn't resist.)

[Wildman Bill]

E Mike: The phone # for John Lamb at Berendson Fluid Power , is it correct as in post #2 ? I've made 3 phone calls with no response in the last 3 weeks. Do you have any part # to make up the kit to turn on the fan when the dash air is turned on. My 04 has 1 hose to the thermal switch on the radiator from the fan motor & 1 return. ( no electrical ) Any info would be appreciated. Bill Hall

_________________________
04 40' MDTS /04PT GT HP or 05 Dodge Dakota 4X4

[EngineerMike]

Berendsen Fluid Power was the vendor for hydraulic pumps and controls to WRV, and John Lamb was the rep assigned to the account. As you can see from that link, they have offices all over the U.S. (there is another page w/Canadian locations. I believe Lamb was in the Seattle office (foggy recollection) so I'd try the Seattle #: 206-575-5100 and then the Spokane#: 509-535-4281 and ask after Lamb since he may have records or recollections about the account. I've seen John's name on the Yahoo Country Coach message board as CC owners follow up on similar fan control problems as recently as 6 months ago.
The fan controller should have a part# tag on it, and Saur-Danfoss has the programming parameters for the part# if you can resurrect that on your coach. The programming says whether your rig was set to call for full fan w/AC.

W/that said, if your rig defaults to full fan w/the controller disabled (the usual program), you could easily splice the 12V leg to the fan controller to a relay's 87a/30 load contacts and run a signal loop from the AC to the relay's coil then to ground. This would have a no-AC effect of fan controller working as usual, then when AC is ON it would cut off 12V to the controller and send fan to default of High; this might require a diode to protect electronics feeding the controller from arcing spikes (engine ECU?);
maybe somebody w/better electronics background can make a suggestion on that??.

[Old Scout]

OK--one more time. It sounds like your 04 was one of the last coaches built [like my 03] with a mechanical [wax valve] fan control system--no electronics are involved, therefore, you can't "re-wire" the "fan controller." Mark Hara is your best bet--he knows the fluid power company in Yakama that "built" the after market kit WRV used to tie a new fluid control solenoid to an existing secondary high pressure switch at the front of the coach [next to and above the evap/dryer tank]. This existing switch came with the ACME a/c system but was not used by WRV in their original application. It was designed by ACME to activate aux electric fans to provide supplemental cooling on the radiators. This preset switch tends to come on a bit earlier than might be desired but it keeps your dash a/c system from over pressure [over 300psi] which would trip the primary switch and kill [shuts-down] the a/c compressor.