2000 Sunrise; Dash AC, "skirts" around wheels, and batteries

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XL Driver

Member
Joined
Jun 21, 2010
Posts
7
Well I got the new motorhome back home.  Overall it was an easy trip.  A few issues; the Dash AC cycles rapidly.  I've already put a pressure gauge on the low side, and as the compressor cycles, it will read anywhere from about 35-85.  Because of this, I didn't charge it.  Besides, it IS cycling, albeit very quickly (about 3 seconds on, 4 seconds off).  Any ideas?  When I've been driving for a while, I do get hot air (not just ambient), but even when first starting out, the air is not cool. 

I've been doing some reading, and I'm thinking I might have an issue with the Evans unit and hot coolant flowing into the "box" as well, but I think that's separate from my a/c issue. 

The "skirts" around the front and rear wheels seem loose.  I was looking at them, and there is one flimsy metal rod from the frame attached to the front and back of the skirt.  The top seems to be secured under a piece of metal and vinyl trim, however, the skirt will shift aft and down after a few hundred miles of driving, or some bumpy roads.  (I don't drive that fast, usually 60 on the interstate). 

On the topic of batteries, I was investigating, and it appears that one of the house batteries had a thermal runaway at some point.  I do believe that this was before I purchased this motorhome from auction, because only one battery was connected when I picked it up (plus the chassis battery).  The entire battery had self destructed; the caps had blown off, it took the paint off the battery compartment, melted the battery casing, and may have even burned within the compartment itself for a bit, because huge chunks of plastic were all together missing.  (pictures to come).

I want to make sure before I replace the battery, that I've taken the steps to make sure it doesn't happen again.  During normal operation, how would I be able to detect a thermal runaway, and is there anytime I should particularly be looking for one?  My thought was that in this case, the motorhome had been sitting for over a year before it was reposessed.  At that point it was started, and the chassis alternator was working hard to recharge the house batteries, which led to this problem.  That being said, the other two batteries in the compartment seem to be fine; no charred wires, melted plastic, etc on them.  I'd appreciate any thoughts/recommendations.  Thanks!
 
There is no real way to tell if a battery is self-destructing. An internal short or a dead cell can cause it, but without some sort of temperature alarm system, you would never know. On the other hand, when the batteries are in decent condition and properly maintained (water in the cells), there is no problem.  If I have an unknown battery to deal with, I just place a hand on it after it charges a short while to sample the temperature. If it is more than mildly warm, there is a problem.

Your dash a/c may have the mixing valve stuck open, allowing heat into the box as you mentioned. Hard to know what else is wrong if that is happening. It's a common problem with the Evans units and some people put a manual shutoff valve in the hot line as the cheap and easy way to solve it.
 
XL Driver said:
The entire battery had self destructed

The exact scenario happened a few years ago to DW's Camry station wagon.  Got a call from her saying the car won't start  ::) - I'll say.  The battery blew up.  Replaced the battery and all was well until we sold the car a few years later.

Maybe your AC high pressure cutout is operating - did you measure the high side pressure?
 
Thanks, I don't have a gauge that I can use on the high side, so I don't know what is going on with the pressure on that side.  For what its worth, I did find this website, that contains a troubleshooting guide for the evans systems.  http://www.evanstempcon.com/tsg_hvac.php

 
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