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dash air not cold
07-26-2008, 01:24 AM
beeohdash air not cold
haven't had to run dash air in quite awhile...tried to use in 95 degree weather but it does not put out any cold air...heater control is in cool position and valve is closed. Just need some hints as what to check as unit worked ok last year.
Bob and Jan Orr
Canadian Barth owners
94 30ft. Breakaway/3116 Cat/ Allison 5 speed/ Gillig
07-26-2008, 01:57 AM
Bill N.Y.If you know what an a/c clutch is, then look at that first.
Start off by starting up the coach and turning on the A/C. Go over to the engine and see if the A/C clutch is engaging and the pump is circulating...
Yes? - Check to see if the cable is fully retracting the heater valve to the off position - make sure the flapper door is moving in the dash as the vacuum venturi may have failed.
No? - with engine running, break out the test light and see if there is power at the a/c clutch.
Tell us what happened, and we'll go from there.
Note: Common sense will tell you that it is very dangerous to work on a running motor. Extreme caution needs to be exercised as you could be severely hurt. If you don't feel safe doing this, and/or there is limited room to work. Back away from the tools and call in a professional.
˙ʎ˙u ןןıq- „ǝןƃuɐ ʇuǝɹǝɟɟıp ɐ ɯoɹɟ pןɹoʍ ǝɥʇ ʇɐ ʞooן ɐ ƃuıʞɐʇ sı ǝɟıן oʇ ʇǝɹɔǝs ǝɥʇ„
|
 | 1990 Barth Regis Widebody 8908 0128 40RDS-C1 L-10 Cummins Allison MT647 Transmission Spartan Chassis |  | 1991 Medical Lab Conversion 9102 3709 33S-12 Ford 460 MPFI C6 Transmission Oshkosh Chassis |
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07-26-2008, 12:27 PM
beeohthanx Bill...we are on the road today but will try to do the tests tonite..
Bob and Jan Orr
Canadian Barth owners
94 30ft. Breakaway/3116 Cat/ Allison 5 speed/ Gillig
07-26-2008, 08:23 PM
RustyYou don't need to have the engine running - just turn on the ignition. You can do a double test by turning the air on at the dash control, then go back to the engine and disconnect the plug to the clutch. It should disengage. Cycle it a couple of times - you'll see the outer disk move... if it's working.
If not, then check for power to the plug; if there's 12VDC there, the clutch is bad. If not, it could be a blown fuse or a broken connection or wire.
If the clutch works, check the condenser fan - with the ignition and A/C still on, check the louver on the left side - you should hear the fan running.
If any of the above don't test good, it's time to visit The A/C Guy. Actually if they do, it still probably is, as the Hi/Lo pressure cutout is malfunctioning or the system's low on refigerant. BTW, on my Breakaway, the condenser fan is powered by a relay in the battery compartment. The A/C clutch is directly wired to the HVAC controls - the blue and purple wires on the bottom of the control box. At least I remember them being those colors - one is for sure purple.
Rusty
"StaRV II"'94 28' Breakaway: MilSpec AMG 6.5L TD 230HP
Nelson and Chester, not-spoiled Golden Retrievers
Sometimes I think we're alone in the universe, and sometimes I think we're not.
In either case the idea is quite staggering. - Arthur C. Clarke
It was a woman who drove me to drink, and I've been searching thirty years to find her and thank her - W. C. Fields
07-26-2008, 08:29 PM
bill hSome AC systems have a pressure switch that fails. A malfunction is often detected only with the engine running. A paper clip can be used to jump the connections for trouble-shooting. Do it only briefly, though, just in case.
.
84 30T PeeThirty-Something, 502 powered
07-28-2008, 01:14 AM
beeohthanks guys...finally off the road and had time to troubleshoot...getting no power (12v) to clutch...its dark now so will check circuit tomorrow...
Bob and Jan Orr
Canadian Barth owners
94 30ft. Breakaway/3116 Cat/ Allison 5 speed/ Gillig
07-28-2008, 01:29 AM
RustyNow it's time to go with bill h's suggestion to jump the hi/lo pressure switch (a common culprit).
If that restores 12VDC to the clutch, it doesn't necessarily mean the switch is bad - low refrigerant will not allow the switch to engage, so if jumping restores power, then a check of the A/C compressor pressures is in order. Typically, these switches cut in at 15 psi or more, and cut out at 300 psi. Static Reed Vapor Pressure on an automotive A/C is around 25-30 psi, so low pressure isn't an issue unless the system is very low on refrigerant. Connecting a source of refrigerant is usually enough to make the switch engage, if that's the issue.
BTW, the switch is usually near the receiver-dryer, a tank about the size of a skinny beer can, located in the front of your unit, above the generator. It'll be the "thingie" with the wires connected, screwed into the refrigerant lines.
Rusty
"StaRV II"'94 28' Breakaway: MilSpec AMG 6.5L TD 230HP
Nelson and Chester, not-spoiled Golden Retrievers
Sometimes I think we're alone in the universe, and sometimes I think we're not.
In either case the idea is quite staggering. - Arthur C. Clarke
It was a woman who drove me to drink, and I've been searching thirty years to find her and thank her - W. C. Fields
07-28-2008, 10:27 AM
Tom and JulieOn my '93 Regency I also have been unimpressed with the dash air so after charging, cleaning, and replacing the compressor on the CAT 3208 and also the dash controls (Chrysler vacuum push button) I learned two things. If your dash air has an intake in the front of the coach on the wall near the passenger seat (or door if you have a front entry) you will find the intake air is open to the firewall and air is drawn in from the front section of the coach. This has a vacuum operated flap that is supposed to seal when you change from Normal to MAX, however they don't. You will be drawing in hot air because the flap does not seal (or may not even close if the vacuum pot is weak) when you turn it on. So if you remove the grille inside and force the flap closed and then insert a sheet metal screw to hold it open and then use aluminum tape to seal it open you will be preventing outside air from entering the coach. That makes a big difference, at least in mine. But never being satisfied and wanting to cool the whole coach while on the road without running the generator (needing to tinker anyway) I removed the condenser (at the back of the coach under the engine compartment) and replaced it with one that is made by Frigi-King that is rated as 40,000 BTU. You may not have two evaporator coils like mine but I wanted to use all the capacity of the engine so this is six times the capacity of the OEM condenser and fits nicely. I expect to get full benefit on the road using both units because this unit is the same kind you see on Rental Car Vans at the airport and they typically freeze out the passengers. Hope this helps.
1993 32' Regency Wide Body, 4 speed Allison Trans, Front Entry door, Diamond Plate aluminum roof &
1981 Euro 22' w Chevy 350 engine and TH 400 tranny
07-28-2008, 12:16 PM
beeohI bypassed hi/lo switch and now have power to compressor clutch. Is my next repair step going to be a visit to an airconditioning shop for a recharge as looks like my pressure is down or needs checking which I'm guessing is not DIY?
Bob and Jan Orr
Canadian Barth owners
94 30ft. Breakaway/3116 Cat/ Allison 5 speed/ Gillig
07-28-2008, 12:25 PM
Bill N.Y.quote:
Originally posted by beeoh:
Is my next repair step going to be a visit to an airconditioning shop for a recharge...?
Yep, Bring it to a shop. You need to get a recharge and have them add a dye to check for leaks. The switch could be bad, but highly unlikely, even if it is bad, they would need to recharge the system anyway.
If it's just seepage, they might not find it right away. The dye will show up when they recheck it later on.
˙ʎ˙u ןןıq- „ǝןƃuɐ ʇuǝɹǝɟɟıp ɐ ɯoɹɟ pןɹoʍ ǝɥʇ ʇɐ ʞooן ɐ ƃuıʞɐʇ sı ǝɟıן oʇ ʇǝɹɔǝs ǝɥʇ„
|
 | 1990 Barth Regis Widebody 8908 0128 40RDS-C1 L-10 Cummins Allison MT647 Transmission Spartan Chassis |  | 1991 Medical Lab Conversion 9102 3709 33S-12 Ford 460 MPFI C6 Transmission Oshkosh Chassis |
Quick Link: Members Only Link To Send Me A Private Message |
07-28-2008, 12:49 PM
beeohthanks guys..next stop will be to a shop for fix...
Bob and Jan Orr
Canadian Barth owners
94 30ft. Breakaway/3116 Cat/ Allison 5 speed/ Gillig
07-28-2008, 05:11 PM
bill hquote:
Originally posted by beeoh:
Is my next repair step going to be a visit to an airconditioning shop for a recharge as it looks like my pressure is down?
Not necessarily. If the switch is telling the truth, you have low pressure. If it is lying, you need a new switch. You can test the switch yourself if you have specs and an air supply or even a tire pump with a gauge. Or you can trouble shoot by substitution and put in a new switch and see how it works. If it doesn't work, you have a spare switch. If you want to give that a go, try to get a part number and see what
www.rockauto.com can do for you. The switches can usually be replaced without pressure loss, but check with someone with knowledge of your particular system first.
quote:
or needs checking which I'm guessing is not DIY?
It is DIY if you or a friend have a set of gauges. You need to guess the future (and evaluate your tool fetish) and decide whether a set of gauges is a good purchase.
There used to be recharge cans of freon on the market that topped off your AC and also had some dye and leak sealer-upper in it. There are still some around if you can find them.
It is a nefarious conspiracy that AC systems no longer have sight glasses.

Geeze, I miss the old days.
Having said all that, our dash air is removed and we drive with the roof air on. You might consider that.
.
84 30T PeeThirty-Something, 502 powered
07-30-2008, 12:18 AM
Creepy CawlerWhile on this subject does anybody have a idea of how many ozs. of freon to charge a 30ft Breakaway?
I have the same problem, no power to the clutch. If you jump the clutch with 12 volts you get cold air. I looked at the low pressure switch and havn't decided witch wires I need to cross. 2 brown, 1black,1 black&yellow.
07-30-2008, 08:05 AM
Gary CarterThis is just slightly left of center on this problem, but with most of us due to the age of our coaches, the AC was designed for R12. That said you should not add R134 to an R12 system without a bunch of work and expense. That said I know of those who have done it and it worked. At a minimum you should remove the remaining R12 and the R12 oil and replace with R134 with the correct oil.
Or you can do as I did and use a product called Enviro-safe. This is listed as a 134 replacement due to legalities, but also works as a R12 replacement and can even be mixed with remaining R12 or R134 and uses either type of oil.
This is only meant to point out to you there are options available.
Due to the fact the most R12 replacements are hydrocarbon (propane/butane mixtures), AC shops avoid them for the most part.
Lots of information available on the internet.
'92 Barth Breakaway - 30'
5.9 Cummins (6B) 300+ HP
2000 Allison
Front entrance
07-30-2008, 03:15 PM
Jim and TereGary, do you know if Enviro-Safe is as efficient as R-12? I have replaced R-12 with R-134 on a couple of cars with all the appropriate valves etc, and found that it did not cool as well as the R-12. I've been told that the reason is that the condenser used for R-12 is not large enough for R-134 and to get close to the R-12 cooling, a larger condenser would have to be installed, assuming you have room for it.
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1985 Regal 29' Chevy 454 P32 8411 3172 29FP3B Gear Vendor 6 Speed Tranny |
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