Community Forums

chris cross · 09-16-2010, 05:14 PM

I'm in a rv repair shop in Aurora, OR. and the teck wants to know how many pounds the system takes. It's an Acme. The temp out the dash is 65 and outside is 74. What else should be checked ?
ASAP THANK YOU

The tech just told me the radiator fan in the engine compartment is not running and the dash air is on high.
I'm going to spend the night in their yard and the techs are going to start tomorrow. Where to look about the radiator fan ?

GOLDWINGER2 · 09-16-2010, 06:15 PM

Mine takes 64 oz of r-12. My fans get power from the A/C control panel through a fuse and relay. The system needs to be charged up for the fans to operate because a pressure switch activates the ground for the relay.
J

Vet · 09-16-2010, 06:22 PM

chris cross,

I had a fan problem with my 2004 bounder and it turned out to be the relay in the chassis panel under the hood. Replaced the relay and all was well.
Vet

Old Scout · 09-16-2010, 06:37 PM

Sorry about not being more precise but I think mine took between 3-4 of the std cans you get at the parts stores. Std amount of PAG oil is about 2 oz. I have done this DIY and despite doing a bunch of reseach on the internet, I remain puzzled about the impact of ambient air temp on freon volume, freon pressure and cooling performance. Assuming the system was purged and vacuum pumped, the freon and PAG quantities are in the ball park. Others on the forum may have better info--the forum is about it as ACME is nolonger in business.

Do a search on the forum on dash air or A/C. Engineer Mike just provided a very good primer on engine fan operations. Basically, if your coach is a 2003 or older, the fan wont run until the engine is at ops temp and a mechanical wax valve opens--on these coaches there is no connectivity between the A/Cs need for airflow across its radiator and the engine fan. 2004 an newer have an electronic fan controller that does monitor dash A/C requirements. You need to read the posts on this topic before letting the RV shop talk you into any "fixes". Chances are they have no idea how the Alpine dash A/C system works.

EngineerMike · 09-16-2010, 08:18 PM

If you have the electronic controller, it may be a one wire unit (actually 3 wires, +12V & Ground on a 2-wire connector, and signal on a 1-wire). The signal wire is expecting a pulse-width modulated 12V signal between 10% and 90%. If the signal wire is unplugged, the fan should default to high, i.e. the control valve closes fully. You may have a more-than-one wire unit (latest ones have IIRC 3 control wires plus pos/neg for 5 total), but unplugging should still send fan to high.
If you or the shop can do the unplug test, and no fan action, then the controller isn't working and you need a new one. The unit looks just as shown on the line drawing below.

Renipladlo · 09-16-2010, 08:25 PM

On the compressor there should be a data plate. If it's there, it will tell you what type of freon, how much, how much oil, operating pressure, things like that. If the data plate is gone, I don't have a clue.

If your system is leaking, they can inject some dye and then you can watch for leaks, fix the leaks and then you fill it up once more and should be done. But with the long run from the back to the front, the leak might be a bear to find and fix.

Good Luck.

chris cross · 09-17-2010, 06:33 PM

Thank you everyone for responding.

The next morning I showed the tec some of the printouts of your responses and here's what he said:

The issue is the expansion valve. The system needs to be flushed and evacuated. The receiver/dryer needs to be replaced.
They estimated that this job was 3/4 of a day.

I will be going to San Diego in a couple of weeks and can make an appointment with Coach Care to address this problem.
I would very much appreciate your thoughts on what I should do.

Thank you,

William Schnieber · 11-01-2010, 06:56 PM

I'm having A/C issues also. My rig is at Colton's Truck Terminal right now.
They are taking care of the akle shift issue, which turned out to be the typical 5/8' bolts in 3/4" holes. The A/C issue I am having is again typical.They recharged the system, evrything is holding but no fan. Sorry for the repeat question but is this normal on a 2005 (late 2004)? Has anyone ever followed through with electric fans?
Do we need to even worry about it. And Chris have you had yours repaired yet?

Vet · 11-02-2010, 07:47 AM

William,

My electric Fans run anytime I put the system in defrost with the A/C switch and recirculate switch on. Used as test to make sure they are working. My manual says Engine heat and/or A/C operate fans as needed.

I tested my Electric Fan relay by swapping it with the Engine start relay.
When the engine wouldn't start, it confirmed my suspicion. Cheap enough to replace and available at local auto parts store.PS: Part number, diagram of relay on relay and contact locations, were exactly the same on my relays. My rig is a 2004 Bounder.

I am still plauged by my ABS problem - If I get an ABS light, my dash air shuts down. Haven't had workhorse recall for brakes done yet, but had break service performed at Lazydays in Seffner, FL and have had ABS problem ever since after first 700 miles. It is intermittent and I can find no correlation except(Possibly Engine heat) causing the issue. As, I can be driving and using dash air and then stop for gas or lunch and restart to find ABS light on and dash air INOP.

Ihope some of the above helps you.

Vet