Custom Coach Conversion AC

[JerryH]

Anyone have a Custom Coach unit (cicra: '75).

Has (3) Copeland AC units.

We disconnected and relocated (2) of the units.  Connected them all back up.  Wired, vac on them, ready to charge, everything.

Did these units have a low pressure switch hidden somewhere?  The compressor, nor fan at the condensor will come on.  The (line volt.) relay leg is powered and the pilot light on the control panel above drivers seat indicates power to the compressor.

I thought maybe a relay was bad -- but two at the same time seems odd.  So we were thinking a pressure switch needs to be re-set.

Custom Coach fully enclosed everything around the compressor with aluminum, providing only a small 4" x 4" access point to charge the unit.  You can barely get your hand in there to check anything. 

Any assistance would be greatly appreciated.

Jerry H.

[tekebird]

Jerry, the top of the alum enclosure should be held down with sheetmetal screws.

And there are a low preasure switch that will not allow the comprtessor to run without or with low ref.

Thanks to Nick I figured this out on mine

[Nick Badame Refrig/ACC]

Jerry,

Teke maybe correct.  Today I was servicing a 87 Marathon Prevost with the same setup as you. His rear unit didn't have a low psi switch.....

His compressor unit also wouldn't come on. What I found was a bad time delay relay. This relay delays the condencing unit from coming on for 120 seconds.

In his case indefenetly! Replaced the relay and it fired up. Now for the center unit evap. with a bad blower motor.. tomorrow I have to remove his entire electrical panel

to even start to remove the evap motor. Marathon burried the evap unit on top the refrig and behind the controls panel......... What were they thinking...

Let me know if you need further help.
Nick Badame

Oh BTW, I forgot to mention, Marathon placed all 3 condencing units under the coach, between the front axles, just behind the spare tire compartment. Lucky Me!

[JerryH]

Ok, following the suggestions from both Nick and Tekebird, I went out this morning to 'git er done'.

The top alum. cover, covering the consensor, compressor and fans was in fact screwed down.  Actually ... one was ... one was not.  After unscrewing the screws I could, then grinding off the others, I thought I could open the unit.  But wait, Custom Coaches rocket scientists also rivoted the front lip as well as screw the top down.

Ok, anyway ... got the darn thing open.  Found the Hi-Lo pressure switch.  Got the Comp. to turn on.

Next dilema.  It won't pull any freon.  I am connected to the suction side, but still nothing.  I looked for a valve, but appears to be none.  Thinking it was an isolated issue, I tried the other unit.  Same deal.

Ok, so now what?  Suggestions?

Thanks in advance for your help.

Jerry H.
'75 MCI Custom Coach Conversion

[Nick Badame Refrig/ACC]

Jerry,

Call my cell  609-827-7331

[Merlin]

Oh BTW, I forgot to mention, Marathon placed all 3 condencing units under the coach, between the front axles, just behind the spare tire compartment. Lucky Me!

Nick ... guess what ... my Prevost was "converted" (term used lightly) by Marathon too.  I have encountered the same "what were they thinking" feeling too.  While unconverting it (ripping the guts out of it), I found many examples of what NOT to do.  Bet they never thought anyone would notice when the handiwork was covered up with glitz.

When I show up in NJ for a bit of work on my three Cruisaires (between the front axles) should I bring a keg of beer to put you in a good mood?  OK ... two kegs?  Huh?

Merlin

[Nick Badame Refrig/ACC]

Merlin,

No Beer!  Just lots of Tanqueray and 7up, I have the Ice....

Nick-

[JerryH]

Problem solved!!

Nick, thanks for taking the time to speak with me today on the telephone.
Let me preface this by saying I am no AC guy.  When I looked at the unit the other day, I did look for a valve at the suction end.  Didn't see what I thought was an obvious valve (to the non AC guy).  I did see a larger cap, but believed that capped the pipe, but in fact capped the valve itself.

Friend came over and within short order got both units running.  Love it ... Icey cold!!  Nick, did confirm the units were originally using R-12, so we used the same thing. 

The bunk section, with the door closed off, gets icey cold -- will be hanging meat in there.  Love it cold.

Now to work on the revamping of the original CC thermostat/rheostat and toggle arrangement into one clean unit.

Thanks,
Jerry H.

*Nick - see you (and Bill & Roberta, and others) in DE in August!!

[darrenayres]

In defense of Marathons, they changed ownership sometime in the 90's, I think. Maybe the newer ones are more intelligently put together. No, I don't own one. However, my brother-in-law has been selling them for 9 years now.

Darren

[JerryH]

A follow up to the AC and rheostat.  So I consolidated Custom Coaches original rear (2) thermostats (1-heat, 1-AC) into (1) line-voltage thermostat.  As noted (I believe) in a previous thread, the nifty heat/AC line-voltage thermostat I bought at Graingers had a three position fan switch (Hi/Med/Lo), which wouldn't work on our single winding motor.  I did find a Leviton (3-position) switch which I thought would work -- but not.  I gave up on using the internal 3-position fan switch for the same fan control technology that Custom Coach used when first built -- yes, a rotary rheostat.

So although not exactly as planned, I did consolodate the, a) heat thermostat, b) AC thermostat, c) Toggle switch and d) Rheostat into just 1) thermostat and 1) rheostat.

It works, life it good.

Jerry H.

[Nick Badame Refrig/ACC]

Jerry,

Thats great!   Gotta love having a couple differnt fan speeds....

Nick-