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What AC compressor for a 1986 P30, 454

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09-19-2008, 06:43 PM
BarthBluesmobile
What AC compressor for a 1986 P30, 454
Hi,
The online parts catalogs and sources show me that there were several choices for the P30 chassis, or for the 454 trucks. It is not clear to me which would be used in a P30 motorhome. There is a choice of "long and thin" and "short and wide" for the compressors. I'd think "long and thin" would work better for the overhead clearance issues.

I am also concerned that there may be different belt groove offsets. On my P30 chassis, the engine accesories on the passenger side are driven by a serpentine belt. On the driver side, where the AC compressor is, the engine accessories are driven by conventional belts. Some 454 trucks in '86 seem to use a fully serpentine system as well.

I need an AC compressor, mine was removed prior to ownership. Could someone with a 1985 to maybe a 1989 P30 454 chassis check what AC compressor they have? If any numbers are visible or if a picture is possible, boy oh boy would I be thrilled!

Thanks!
Matt

ps: I just thought I should also check with my lock GM Truck Parts Counter Guys.....


1987 Barth 27' P32 Chassis
Former State Police Command Post
Chevrolet 454
Weiand Manifold, Crane Cam, Gibson Exhaust
09-19-2008, 07:59 PM
Gunner
quote:
Originally posted by BarthBluesmobile:
"It is not clear to me which would be used in a P30 motorhome. There is a choice..."
For what it is worth: my 1986 34' Regal w/454 had a Japanese A/C compressor (Sanyo??) and memory tells me it was mounted slightly higher and closer to the engine c/l (above the valve cover) on the engine than GM automobile compressors.


"You are what you drive" - Clint Eastwood
09-19-2008, 10:58 PM
bill h
quote:
Originally posted by BarthBluesmobile:
"It is not clear to me which would be used in a P30 motorhome. There is a choice..."

quote:
Originally posted by Gunner:
For what it is worth: my 1986 34' Regal w/454 had a Japanese A/C compressor (Sanyo??) and memory tells me it was mounted slightly higher and closer to the engine c/l (above the valve cover) on the engine than GM automobile compressors.


I can post a picture of mine if an 84 would apply here. It has a 2-groove Sankyo mounted as Gunner describes. Only the rear groove is used. The belt wraps the middle crank pully and the aft groove of the compressor and water pump.


.

84 30T PeeThirty-Something, 502 powered
09-20-2008, 12:50 AM
Rusty
'86 through '88 chasses (which would be through '89 model year motorhomes) seem to be cursed with a variety of choices. My '89 SOB Class C, on a Chebby 3500 HD chassis had no less than five choices of belt arrangements, and sevent A/C compressor choices. With the 5.7 L engine without the serpentine belt, there were five compressor choices. Mine took the sixth, unlisted.


Rusty


MilSpec AMG 6.5L TD 230HP; built-to-order by Peninsular Engines:  Hi-pop injectors, gear-driven camshaft, non-waste-gated, high-output turbo, 18:1 pistons.  Fuel economy increased by 15-20%, power, WOW!"StaRV II"

'94 28' Breakaway: MilSpec AMG 6.5L TD 230HP

Nelson and Chester, not-spoiled Golden Retrievers

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In either case the idea is quite staggering.
- Arthur C. Clarke

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09-22-2008, 09:01 PM
Ray
Food for thought...

I removed my AC compressor , evap, ect. and just use the generator to run the house air if I need it. Engine runs much cooler and generator uses less fuel than the extra load on the 460 engine that I have.

Ray


1990 28' Barth - John Deere/Oshkosh chassis with 460 Ford
07-20-2025, 01:27 PM
914rrr
I'm picking up my recently purchased 1980 29' Barth P30 454 next week that needs dash AC repair. Any advice, potential part / model numbers for AC compressors, brackets, dash units, blend door parts, etc. would be greatly appreciated.

I could also use similar advice for the wiper assemblies, as neither work at this time.
07-21-2025, 12:01 PM
Duane88
Can understand your desire to have the dash A/C, but it is an old R12 system, and they really never were very effective, I had an 86, 81 and now a 71 Barth. I converted or had converted an 86 Winne, it was a typical Chevy P30 system on a GMC chassis, poor to begin with and after it was converted to R134a it was even worse.

The old compressors can run on R134a if they are working, they need to have an oil change, and the system purged. The Experts say to change the expansion device, but I think that's not necessary

Like most of us with old R12 units, I just remove the compressors and brackets, get belts that fit without the A/C system. When I need or want A/C, start the generator and run the roof unit. Did this on all 3 of my Barth's. I left the condensers and evaporators intact but sealed just in case I ever wanted to go back to the system.


1971 24 ft Barth Continental
P30 chassis
350 engine
07-22-2025, 09:22 AM
BarthBluesmobile
914rrr! Find a truck with a 454 in a junkyard with the parts you want, that's a starting point. You will be assured of having compatible parts and brackets, and getting a wiring and hoses as guides for your work is possible too.

I won't be able to get to the junkyard for a few weeks, but i know of a 1984 P30 RV near me. I think that might have the same bracket and belt setup as yours.

What is the present situation on your rig? Is it missing a compressor only? Or did you get a gutted project?

happy motoring!
Matt


1987 Barth 27' P32 Chassis
Former State Police Command Post
Chevrolet 454
Weiand Manifold, Crane Cam, Gibson Exhaust