Community Forums

rickmc · 09-06-2020, 06:50 AM

We picked up our new Newmar Baystar last month. While driving home, I noticed the dash air was blowing warm. I understand Florida summers are a bit toasty. When we arrived home I checked under the hood and found what I believe to be the problem.
The cheap flex hose material used to get cool air to the vents from the unit was hot to touch! Has anyone changed out these hoses to an insulated hose or wrapped insulation around the OEM hoses?
If so, I'd appreciate your inputs on any materials used or other remidy suggestions.

Kahoona · 09-06-2020, 08:35 AM

2 layers of that silvered bubble wrap should do it. It is sold at auto stores and the Home Despot's auto section in hot areas. you cut it to size then seal the seam with silvered tape or a really good duct tape like Gorilla. A couple of zip ties in curved places won't hurt. Sometimes the neoprene pipe wrap works too but it can be hard to find it in a large enough size. The pipe wrap can be taped and slid back into tight spots where taping would be hard.

It won't hurt to do this but if you are getting that kind of cooling loss you may need to have the system looked at. You may want to measure the difference between the temp at the intake and at the vents. Do it with the system on MAX or Recirculate. Do some research to see what the difference should be but I am used to seeing at least 30f

rickmc · 09-06-2020, 04:33 PM

Quote:

Originally Posted by Kahoona

2 layers of that silvered bubble wrap should do it. It is sold at auto stores and the Home Despot's auto section in hot areas. you cut it to size then seal the seam with silvered tape or a really good duct tape like Gorilla. A couple of zip ties in curved places won't hurt. Sometimes the neoprene pipe wrap works too but it can be hard to find it in a large enough size. The pipe wrap can be taped and slid back into tight spots where taping would be hard.

It won't hurt to do this but if you are getting that kind of cooling loss you may need to have the system looked at. You may want to measure the difference between the temp at the intake and at the vents. Do it with the system on MAX or Recirculate. Do some research to see what the difference should be but I am used to seeing at least 30f

Thanks for the response! I’m going to HD tomorrow! I’ve got a infrared thermometer and will do check delta T. Thank again!

THenne1713 · 09-07-2020, 01:25 PM

Air duct NOT the problem, I suspect either 1) AC NOT cooling properly, or 2) OUTSIDE AIR VENT Open (vs recirculate the Interior COOLER air)= "MAX COOL", or 3) (If equipped) Damper DOOR to HEAT Coil NOT closing properly or 4) (if equipped) Heat Control WATER VALVE not properly shutting off Hot Water FLOW. (Some use damper, some control water flow). If you can safely reach/ touch the larger metal SUCTION LINE to compressor, it should be very COOL or cold to touch while running, after running for a short period if cooling properly. Other issues are (2, 3, 4 above) can be VACUUM HOSE/ Vacuum leak problems. Hope this helps

Sweetbriar · 09-09-2020, 06:53 AM

Quote:

Originally Posted by rickmc

We picked up our new Newmar Baystar last month. While driving home, I noticed the dash air was blowing warm. I understand Florida summers are a bit toasty. When we arrived home I checked under the hood and found what I believe to be the problem.
The cheap flex hose material used to get cool air to the vents from the unit was hot to touch! Has anyone changed out these hoses to an insulated hose or wrapped insulation around the OEM hoses?
If so, I'd appreciate your inputs on any materials used or other remidy suggestions.

Vent air ducting routed outside of the coach interior? That's really strange. Even my low budget Hurricane has all the ducts buried behind the dash but inside the coach body. Even the windshield defrost ducting is inside the coach. Subjecting the ducts to the outside environment can effect efficiency for both heating and cooling.

Hot to the touch is also unusual. Warm maybe but hot means something is adding heat beyond the outside environment. Any chance of posting a picture of the ducting you found?

Fugitive861 · 09-10-2020, 08:30 AM

Where is the heat coming from? I'm assuming all your duct work us under the dash on the interior of the coach, right? I'd look to see where the heat is coming from. Maybe doghouse is not sealed well? I think insulating the ac hoses, although may help, is not addressing the root problem. Tell us what you find and good luck!

mikee409 · 09-24-2020, 08:05 AM

On engine start up my in the vent AC temp gauge will drop into the green 45 deg. section.
After the engine warms up the vent temp rises to 60 deg and stays.
I used clamps and squeezed off the hot water flow lines to the heater core and the temp still stays at 60 deg, so I know the heater control valve is not the issue.
The AC is set on max & recirculate. I even blocked off the outside air intake in case the damper wasn't closed all the way. Still no change.
I put a jumper on the temp probe going into the Evans?Tempcon AC box so the thermostat wouldn't turn off the AC compressor.
Still the exit air temp wont drop below 60deg F.
I connected a Freon fill gauge to the low side/suction side of the compressor. It's showing 40 psi and in the green good level of Freon. I notice that the compressor is still cycling on and off even with the Evans thermostat bypassed?
So question is ... What would still be telling the compressor to cycle on and off. It is if the AC system thinks its reached the low temperature setting and turning off the compressor.
Is there another thermostat some where else?
This is a new motorhome with less than 7000 miles on it.
Our old 2001 Newmar with an Evans AC unit on it would run in the green 45 degree zone with no problem even when the outside temp was 100F.
Any one got an Idea whats going on?
I'm taking it back to the dealer for warranty work but my confidence level they can fix it is very low.

Mikee

GypsyR · 09-24-2020, 12:21 PM

The most common cause of compressor cycling is simply low refrigerant.

mikee409 · 09-24-2020, 03:23 PM

Quote:

Originally Posted by GypsyR

The most common cause of compressor cycling is simply low refrigerant.

Gypsy, I experimented with the freon charge in the system.I tested the system with as low as 30 lb of freon then,35, 40,45,50 nothing changed hardly. The only thing was with 50 lb charge the pressure started to increase as the engine ran & cooling started to fade with vent temp starting to rise< " over charged I think"
I agree,usually the compressor short cycles with a low charge but not in this situation. I'm wondering if the low charge safety switch is defective or a hi pressure switch in the system. I even sprayed water on the condenser coil by the radiator to get some cooling to the hot freon & that didn't help either.

GypsyR · 09-24-2020, 07:41 PM

Gotcha. Wasn't sure how familiar you were with the system. Your assessment of charged and overcharged is spot on. Without being there in person I am starting to suspect a faulty expansion valve. Or orifice tube, whichever yours has.
Mine was sort of similar but turned out that the compressor was weak and could no longer develop the proper pressures. It actually looked OK on the low side, I had to hook up an actual gauge set and observe the high side too before I realized exactly what was up. Apparently a fairly common failing for seven cylinder Sandens of my coach's era.

THenne1713 · 09-24-2020, 11:37 PM

In my 94 Nissan 4-cyl, (owned since new, so now 26-years experience) has told me that FIRST SYMPTOM OF LOW radiator ANTIFREEZE/ coming overheat (DESPITE DASH TEMP GAGE STILL SHOWING NORMAL 3/8-GAGE) is reflected in high AC Supply temp. However, not sure if that is kicking a HI-PRESS SWITCH AND TURNING COMPRESSOR OFF OR NOT, as NOT my daily driver now, and not now any overheat issues. OTOH, years back, selling auto parts, many inquired about "Why do I not have any HEAT sometimes" to which I responded, "Check antifreeze level in radiator, and check water pump/ hoses for small leak tracks, as it leaks while driving". HOPE this helps?

Flavius · 09-27-2020, 03:08 PM

I have a similar problem on a 2020 JAYCO Precept Prestige. Since new, driving it home from dealer, we noticed that air-conditioning from dash vents were super cold until about an hour into trip. It would then start blowing ambient air and cycle back and forth. First Ford truck store said it was a cracked schrader valve and a leak. They fixed same and one hour into trip home - it did same thing. Took it to a second Ford Truck place and they have had it almost 3 weeks with not a clue. After a week of supposedly checking different components and servicing they tried to tell me that they could find no problems. I had them run the air for 2 hours and to check it after one hour and then again at the second hour. They were able to duplicate the problem, but not fix it. I have been in touch with FORD motorhome customer service, JAYCO, and dealer. No solution and no callbacks! Not a happy camper! Please also read my post on F53 front end kingpins!
Very poor quality control or customer service.
This is our second F53 chassis, drove for it 5 years and about 50K miles with no issues with chassis.