[Jerry]

I purchased a used 1996 38 foot Newell RV and trying to figure out how the AC works. I turned on the generator and the AC worked, but the two back of the air vents had not air coming out and didn't appear to be any air coming out in the bedroom.  I didn't have it plugged in, so the generator is probably all that makes it the AC work.  The engine running makes the front AC work, but I don't think it makes the larger unit work.  Can anyone explain how the AC works with the front, verses the middle and back?

Thanks,
Jerry

[ccjohnson]

On our '92 there is a thermostat for each section / AC unit. The rear / bedroom is located on the wall near the "Newell" clock. The mid / galley unit thermostat is behind a small "door" just left of the refrigerator. The front is located behind the drivers seat on a wall at the end of the sofa. It also controls our front propane furnace under the sofa. Yours may be a bit different though.

[Fulltiming]

Congratulations on getting #428, the shortest Newell ever built with a Detroit Diesel Series 60. First, the dash air is the only one that runs off of the engine. The other AC units run off of 120 volt power, either when plugged into 50 amp shore power or running off the generator.

Since you have the smallest Newell built during that time period, I don't know how many AC units you have. They would be in the bays. You likely have a single 13.5 k btu AC that serves the bedroom and bath and a dual AC unit that serves the kitchen and salon. The compressor and condenser for each unit are in the bays. There should be a thermostat for the front AC, probably in the salon and one for the rear AC, probably in the bedroom. They are NOT tied together so if the rear AC is not turned on, you will not get any air out of the vents in the bedroom and likely the bath. If the front AC is not not turned on you will not get any air out of the vents that are located behind the valence panels that run above the windows from the kitchen up to the front overhead compartment. I have basement airs but they are the older Dometic units so mine may be somewhat different but you will need to have both thermostats turned to cool to get cold air out of all the AC vents except the dash vents.

[HoosierDaddy]

The main engine would power the “dash air” ie the vents on the front instrument panel. The other “house A/C units would have separate thermostats for the zone they are conditioning. The house units are powered by the generator or by shore power.

[folivier]

I inquired and spoke with the seller about your coach a few months ago before I bought our Foretravel. IIRC he told me the rear air conditioner (which is an SCS according to a picture he sent me) was tripping the breaker after 10 minutes running. Richard could possibly help you troubleshoot this but it has common AC parts and you can actually remove the entire unit from the basement to work on it. There are a few easy ways to upgrade these units to make them more reliable. Read through this air conditioning section and especially this thread: http://newellgurus.com/showthread.php?tid=3252
Congrats on your purchase, it sounded like it was a nice coach.

[folivier]

Another thing I think the A/C vents actually blow air into the passenger side valences over the windows. Those round holes over the fridge are just for venting and not A/C.

[Richard]

Hi Jerry,

Welcome to the Newell family. The learning curve can be steep and frustrating, but the members here will help you.

First of all, in order to help you best, will you tell us a little about yourself. Specifically, is this your first motorhome, what is your mechanical and electrical experience, and do you know how to use a voltmeter? I am not trying to be insulting, just trying to target the help to the audience.

Ok, you have SCS brand basement air conditioners. Since you have somewhat of a unique coach, I am not going to speculate on how many and their location. We will figure that out together.

Let's start with the simple stuff. How many thermostats do you have? And, when you look in the AC breaker panel, how many of those breakers are labled AC?

Next, and this has bitten ALL of us. Look at the panel of switches above the microwave. Look for a switch labeled Heat On-AC Off or Heat Off AC On. Make sure that switch is in the AC On position. You may not have it. Around the time your coach was built Newell started installing a 220V heating element in the Aquahot system to provide heat and hot water. The campsites do not provide enough amperaget to run both AC units and the 220V aquahot.

Next, when you located and counted the AC breakers in the panel, were any of them tripped. If one or more were tripped, then reset them.

On the thermostat, you will likely have Auto High, Auto Low, On Low, and On High on the slide switch on the right side. You will likely have Cool, Heat, Off, and Fan on the switch on the left side. I say likely, because a PO could have changed the Tstats.

Turn the left switch to fan. Turn the left switch to ON High. What happens? The blower should come on and air move from the vents.

Assuming the blower comes on, let's run the next test. Turn the left switch to cool and the leave the right switch ON High. Press the MODE button till the litte arrow on the screen aligns with cool. Press the down button until the setpoint is about 5 degrees below the temperature in the coach. It will take approximately three minutes for the tstat to repsond. It will seen like an eternity.

What happens? This is what should happen. The inside blower should be on and air coming from the vents, you should be able to hear a blower running from the AC unit OUTSIDE the coach. And the compressor should kick on. Look at the Ammeters over the driver before and after the unit activates. What are those readings.

Last comment until you run these tests. I have seen the SCS basement units mounted in different locations. On some of the early coaches like yours, the units were mounted in the center of the basement, perhaps even hidden behind carpeted panels. You are looking for a rectangular box, with two insulated elephant snouts leaving the top. Those snouts route the cool air into the ductwork.

Answer the questions I asked and we can go to the next steps in troubleshooting.

Do you have an SCS manual in the literature that came with the coach. If not use the search engine on the forum, type in SCS manual, and you will find a thread with a link to a copy. It's a good time to learn how to find the treasure trove of information on the site.

Finally, Rhonda and I are traveling in Montana. In three more days, I will be in the land of NO phone or internet, so my replies to your issue may slow down.

[hexspeed]

Hey Jerry -- I know Richard will get you there with a much more thorough understanding of your system that will benefit you in the future, but as a quick fix, have you considered calling Russ and asking for a short lesson in turning on your A/C ?  When I was looking at his (now your) coach, he seemed like the kind of guy who wouldn't mind having a quick conversation.  At least when you get back to Richard, you'd know whether you have a real problem or just missed flipping a switch somewhere.

Jim

[Jerry]

Thanks a bunch everyone!!! I didn't realize there was a back thermostat and will turn it on later today. Russ walked me through things, but was a little overwhelmed by all the stuff to learn and forgot some of the information. Russ did tell me it nocked the breaker after awhile, so I will see what happens.
Another question, when going down the road do you need the generator on to run the back and middle AC, or will the engine alternator work? Can the AC run off the house batteries without the generator? Last, I have it plugged into the house with a splitter plugged into a 115 and 130 amp circuits. Will this power the AC or cause problems, because the coach seems to like like a 50 amp service?

I took the coach to the local RV Center and the service department didn't understand the coach and were not helpful. Is there any service centers or individuals in the Ohio area that could work on the coach? Thanks again, greatly appreciated.

[folivier]

To answer a couple questions. Yes the generator will need to be running to run the back and middle AC since these are powered by your 50 amp 120 volt system (similar to an AC in a house). Only the dash air will work with the engine running. Most owners run the generator while driving if it's hot enough to need AC, that's what it is designed for.
Not sure what type of splitter you're using but if it supplies 120vac on 2 different legs then you can probably run 1 or 2 AC's. It shouldn't hurt anything to try. Just watch the voltages at the panel above the driver's seat. If they drop below 110 volts then I wouldn't take a chance to run the AC's. Or just run 1 AC.
If you can find an experience Newell owner near you it would be very helpful to spend some time with them to learn the systems on your Newell.