Cruise Air Problem

Well we picked up the new to us 1991 Liberty yesterday. After a six hour PDI following Jon's list, everything looked good and we fired her up and came home. Got in late and I plugged the coach in up at the house. Had to use a 50 amp extension cord that I had never used and found out this morning that I had reversed polarity because of the extension. I did not see this situation until this morning when I went out to move the coach to the bus barn. The only problem is that the SMX control for the front Cruise Air has no indication power to it. Nothing lights up on the SMX panel. The breaker inside the coach for the front Cruise Air was not tripped and I have tried resetting it several times. Is their another breaker or reset button for Cruise Airs? I have looked everywhere I can think of with no luck. I have just about every bit of documentation that you can think of with one exception. There is no Liberty Owners Manual with the coach. I have the Liberty electrical schematics and the Cruise Air users book but no help. Any way to test the SMX? What would I get into if I tried trading out the SMX from one of the other Cruise Airs? I guess the first thing is to check the voltage at the back of the non working SMX. I'll go do that now. Any help appreciated.

Mel Torme,

First of congratulations on the new Liberty. Great choice.

I know on my '97 Liberty the main electronics for the SMX panel was down in the bay. And in those individual control boxes there was a very sensitive circuit board that was the brains for the unit. SO I'm guessing changing the controller in the bus probably won't do much good as the issue is probably the board in the bay. Unless there's another circuit breaker that has been overlooked.

Does the rest of the bus electrical system seem to be ok.

And probably need to ask Santa for one of these as it will protect you in the future.

http://www.prevoman.com/Pages/Cool%2.../Surgepg1.html

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Hopefully more of the brain trust will chime in with additional ideas.

Mike

Mel Torme,

Do the CruisAirs work when the generator is running or have you only tried it on shore power?

I too own a Prized Liberty Coach (I may need to sell it or trade it someday) and I went thru a similar situation on my first outing. Mine is an elegant lady and not only does it have breakers for each cruise air and SMX controls, I have a touch screen on the dash which controls the on and off of the cruise airs. Breakers can be on, but if the dash switches are not on the cruise airs will not work.

My main controllers are as Magnifincet Mento Mango Mike described in the front bay ceiling - I have never been into them and don't want to.

I hope you have switches you haven't found and just need to turn them on.:cool:

Well, if the "black box" for the Cruise Air is in the front bay I can't find it. The one for the middle unit is mid coach back under the kitchen counter but that unit is working fine.
Good thought, Jerry, so I went out and tried running the generator. Same result.
All other 120 volt stuff is fine.
There is no power to the SMX controller so switching would be kinda stupid. Now I do lots of stupid stuff but I think I'll skip it this time.
I think I'll go drop the front bumper and hunt the control box. Is there a reset button on that deal?
No touch screen on this one, Roger but thanks anyhow.

Ted,

If you have an Elegant Lady make sure the switch on the LH dash panel for the cruise air is on.

Also, I don't know if all Libertys (12V and 24V) have them, but on my coach there are fairly bog relays behind my panel that make a distinct engagement sound when the cruise airs are powered from the switches on the front panel.

I leave the CBs in the panel on all the time, and the SMX panels are on all the time and I control the cruise airs from the dash.

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And probably need to ask Santa for one of these as it will protect you in the future.

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If I understand the post, the gadget unfortunately wouldn't have detected this problem. This unit will tell you if there is an issue with the power "at the post". If I read this correctly, the problem here was a miswired extension cord. I guess one could plug the unit into the extension cord, and it would have show the problem at that point, but we generally expect our wires to be fine, and the intent is to check for problems with the incoming voltage.

Still a great device to have!

Ray

No, Jon, the only switches for the Cruise Airs are the ones in the breaker panel and the ones on the SMX control panel.
Not sure what is going on here, but will have some time later in the week to track it down.
Another unusal thing I found today is this. On the drivers side bay for the OTR air. The one that has to be unscrewed, the louvers that alow air into this bay have been closed off. I hate to screw up the OTR air/heat, but why would someone block off this vent? Might just leave it as is for now.

I have ours blocked off for summer, helps the a/c get colder.

There is a manual damper in there that is adjustable from full open to full closed but in full closed quite a bit of outside air is still drawn in.

Could probably allow some outside air in for winter.

Ray,

The bus should always be plugged into this unit directly. It will detect, among other problems, reverse polarity and will refuse power to the coach.

Mike

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The bus should always be plugged into this unit directly.

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Just so I'm clear. Are you saying that the order should have been:

bus -> device -> extension -> house plug

or

bus -> extension -> device -> house plug


I'm guessing that the latter would NOT detect a failure, as it's on the wrong side of the detection circuits? Does the device detect miswired on the bus side too? That would surprise me ....


Ray

The louvers in my coach are air acutated so I can switch them open or close depending on what is needed. If your cruise aire does not turn on, check for voltage first. My controller over my front door is tempermental and I actuallly have to tap on it a few times to get it to read and work.
Mango, what Jon is saying is correct, Your unit is plugged in outside at the power source, it does not read anything on the cord side to the coach. The best thing in this case is to have surge protection in the Coach where the cord connects to the transfer switch.

Ted
the SMX wires go to a Box, I forget the name of them but they are labeled something like PMA. Mine had two under a couch in the salon and the thrid one behind the TV in the bedroom. I think they are position close to the condensors. It is a white metal box that has a cover that covers two sides and the top. Inside you should finds a fuse. I had a problem but after looking inside all the boxes I found no problems. I took the SMX off the wall and found that one of the wires in the cable had come off, reattached that one wire and I'm up and running.
GregM

Ted,Liberty modified the bay on the drivers side to recirculate 100% of the AC or heat.I think this happened when r12 freon was no longer the standard.It works great with the 134 freon,on other coaches that have not closed off the fresh air mix the temperature difference is between 8-10 degrees less.On a 98 degree day last summer I could maintain 70-72 degrees inside my Liberty with the OTR air.

To add to Jack's post, our 87 Liberty had the outside air vent capped as does my 97. The 87 used R12, and the current one 134A.

Capping the fresh air intake makes the system cool the inside of the coach more efficiently (it is like the max AC position on a car).

Ray,

bus -> device -> extension -> house plug

Is correct. If you somehow rewired your bus on inside, would it detect a reverse polarity? Can't answer that. But if you try it - let us know. ;)

Mike
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So the consensus is to leave these vents blocked off. Easy enough.

Mike, I bought the high dollar plug in deal this morning. Kinda like closing the barn door after the horse gets out. But, there's always another horse.

I fully expect the Cruise Aire to start working again when I plug up with the new (high dollar) deal since Mike has such high praise for these things.:):)

These self inflected problems are such a fun way to learn the bus. I think I'll go out and see what else I can fiddle with till it breaks.:)

"These self inflected problems are such a fun way to learn the bus. I think I'll go out and see what else I can fiddle with till it breaks."

It is clear to me that Ted is about to learn why all of us who have done this can feel confident answering questions. At least those of us who have the capacity to learn from our misteaks.:o

I believe that the majority of the stuff we've learned about our busses have been the hard (read expensive) way.

But then we'd have nothing to post about except flatulence.

Mel Torme I wouldn't hold my breath on the the cruise air working after the device is installed.

Mike