Community Forums

ronboc · 09-24-2005, 03:28 AM

Hi all -

I've about wore a hole in my head, scratching it so much over my new problem. I've done searches here, but haven't found the nugget-details I'm looking for.

As I'd posted earlier in another thread, I have a cutoff valve in-line with the hot water for use during the summer when I need AC, and it worked well. Recently, however, I noticed that I gradually (over a period of maybe 3-5 minutes) would lose effectiveness of the dash AC, to the point that it was actually blowing HOT air out the AC vents. If I shut it off and then retry in another 3-5 minutes, I'd get the cold air back, but it would start to slowly get hot again, and so on. Everything else seems to be working ok (electric fans, core-fan, no clogs/bugs, etc), but it just won't make the cool-stuff for very long.

Now, why would it blow HOT air when the hot-side was cut off? (I didn't have a thermometer stuck in the vent to check the actual temp, but I guarantee it was a whole lot warmer than ambient - which was about 90 outside).

And more importantly, where do I go from here? I'm competent with electrics and mechanicals, but not with troubleshooting something odd like this. Any diagnostic help is appreciated. I suspect it'll have to go to the WCC-doctor for eventual fixing, but I'd like to see if I can fix it if it's something I can handle, or maybe help the eventual repair-tech folks get it solved quicker (I hate making an appointment and then having to leave the MH for several weeks, just sitting there).

TIA,
Ron

ronboc · 09-24-2005, 03:28 AM

Hi all -

I've about wore a hole in my head, scratching it so much over my new problem. I've done searches here, but haven't found the nugget-details I'm looking for.

As I'd posted earlier in another thread, I have a cutoff valve in-line with the hot water for use during the summer when I need AC, and it worked well. Recently, however, I noticed that I gradually (over a period of maybe 3-5 minutes) would lose effectiveness of the dash AC, to the point that it was actually blowing HOT air out the AC vents. If I shut it off and then retry in another 3-5 minutes, I'd get the cold air back, but it would start to slowly get hot again, and so on. Everything else seems to be working ok (electric fans, core-fan, no clogs/bugs, etc), but it just won't make the cool-stuff for very long.

Now, why would it blow HOT air when the hot-side was cut off? (I didn't have a thermometer stuck in the vent to check the actual temp, but I guarantee it was a whole lot warmer than ambient - which was about 90 outside).

And more importantly, where do I go from here? I'm competent with electrics and mechanicals, but not with troubleshooting something odd like this. Any diagnostic help is appreciated. I suspect it'll have to go to the WCC-doctor for eventual fixing, but I'd like to see if I can fix it if it's something I can handle, or maybe help the eventual repair-tech folks get it solved quicker (I hate making an appointment and then having to leave the MH for several weeks, just sitting there).

TIA,
Ron

DriVer · 09-24-2005, 06:55 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by ronboc:
(I hate making an appointment and then having to leave the MH for several weeks, just sitting there). </div></BLOCKQUOTE>Ron, In that case go to an AC Shop.

The systems are basically all the same. Now if the tech there tells you that you need a major component then by all means:
(a.) You'll know what you need and
(b.) You can then make that appointment with the confidence that you will know what's wrong and you can tell the WCC service center that you had your MH looked at at a competent AC shop and they said ABC was wrong or bad.

Otherwise if the AC shop can simply tighten something or recharge your system everything should be OK at that point and your "off" no delay. Grant it that it'll be out of pocket but what's it worth to you? "Time" OR "Money"? It's your call.

PS: Are you moving forward at a good rate of speed or or you standing still? My AC doesn't work all that well while standing still idling. That's OK for me because I know what to expect. This summer traveling up Route 95 in Arizona and California to Needles the air outside was 3 "digits" hot most of the time and the dash AC performed well (without the aftermarket auxiliary AC cooling system).

Oemtech · 09-24-2005, 07:34 AM

Two things come to mind.

1) The valve that shuts off the water to the heater is "prone" to malfunction. IE - it leaks, does not work all the time or fails completely. To check, get the engine up to temp and see if the hose on the heater side is warm. If so, it is probably a bad valve.

2) In most coachs the outside A/C air intake is in engine bay. So, in slow moving traffic you get hot air from the engine. Also there is no insulation on the box that covers evaporator coils. Run the A/C on max air as it will draw the air from the inside the coach and not from the outside.

WCC also make a add on A/C unit to the tune of about $600 plus install.

Lastly, you have a failed component in the A/C system.

DickNJo · 09-24-2005, 08:38 AM

Are you in a high humidity area. If so you may be icing up the chiller coils. I have had this problem on the oregon coast when the AC was improperly set up. The symptoms are as you describe.

ronboc · 09-26-2005, 03:58 PM

DriVer -
Hmm. Yes, I think I was traveling slowly at the time, but wasn't paying much attention to the speed right then. Never had that happen before. Any thoughts on why, or if the 'aftermarket kit' that's being talked-about will help?
You're saying that if I get it back up to speed, it may just be an airflow issue?

oemtech -
I've already 'helped' the system as much as possible, by putting in a shut-off valve in the hot-water line to ensure the regular shutoff is doing its job.
And you're right, it's sucking hot air. Too bad they didn't make it like a car and draw from the cooler high-pressure area at the windshield base. I may install a snorkel to draw in cooler air.

DicjNJo -
Unfortunately around here this time of year, humidity is one thing we'd be happy to see (especially in the form of those big wet droplets). But I'll keep an eye on it for icing (sounds strange, I know, when today it was 102!).

All -
Thanks for the suggestions and help, I'm slowly sinking under all the minor problems that are cropping up and threatening to overwhelm me. Getting so I don't know what to worry about next, or to realise something may indeed be a biggie.

R

DriVer · 09-26-2005, 05:24 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by ronboc:
You're saying that if I get it back up to speed, it may just be an airflow issue? </div></BLOCKQUOTE>R, yes exactly. Observe the performance of your AC while traveling at highway speeds. I use a laser temperature instrument and I can easily meter 20? less in temperature from the registers than the air outside the coach. This is usually about as good as it gets.

Like I said, I ran in 114 to 118 temperatures and the AC system's performance was acceptable w/o the $600 after market auxiliary cooling system.

Observing a 95?+ degree readout on my temp/compass I crank on the generator and run the house air and the defroster fans to move as much air as I can.

No complaints!

ronboc · 09-27-2005, 11:29 AM

Ah- HA! This is even better than I'd been hoping-for, DriVer! I've had a remote temperature reader on my Christmas-list for a couple years now, but Santa keeps overlooking it. Maybe if I show a cost/benefit comparison between the $100 sensor and the $600+ ac-upgrade, I think it'll tip the balance. Many thanks.

In all seriousness, what is involved in the upgrade-kit? I've done some looking here (and elsewhere), but haven't found much specifics. Can anyone chime in with help, or a usage-report?

Any idea why the stock AC doesn't work well at slower speeds? I'da thought the electric fans would preclude any airflow issues. Is it something else?

And yes, in the hot hot hot weather, the big AC's are on too, no matter what!

TIA,
Ron

BEBOP · 09-29-2005, 12:10 PM

HI ALL,
I have a similiar problem, (question) but different.
My dash AC works great however there is no adjustment on the rotary temp control. It is either icy cold or rotate it about a half inch and the change is to warm or hot air. There is no separation between hot and cold. It is one or the other at that point on the rotary temp dial. Any ideas out there?
Bebop

Oemtech · 09-29-2005, 07:06 PM

Bebop - That is probably the heater control valve that I talked about. I am going to change mine out as soon as I find a good replacement. I may put a cable operated one in.

FloraBama · 10-06-2005, 05:10 AM

I've been in the A/C shop at Lazy Days for two days now and the problem has not been isolaed yet. The dash air has really never worked since purchased new 11 months ago--I even get warm/hot air when on Vent.

I also have a minor oil leak and they are thinking the engine has been running hot all this time (10,000 miles) and that may be the A/C problem; I don't think so.

They have ruled out he Evans hotwater flow valve which is what I had suspected at first.

Will keep you posted on the outcome.