Foretravel Owners' Forum For owners and Fans of Foretravel Motorcoaches September 14, 2025 ...

Dash AC belt squeal?

September 01, 2013, 02:46:02 pm

Cranked engine, warmed and then turned on dash AC just to run it a bit before go on highway.  Immediately got a squealing noise from the rear engine compartment.  If I turn the dash AC off, the noise stops.

I would expect that it is something in the AC like a bearing or such? and thus should not be run, for if run it might seize up and stop the belt from whatever other function it provides?  Sound reasonable as a guess for me, but should I do something else?

(time to leave the mountains, will need some AC when get to Texas!)

Mike

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Re: Dash AC belt squeal?

Reply #1 – September 01, 2013, 03:49:52 pm

Mike,

Need to determine if this is a belt squeal or noise from the compressor itself.

If belt squeal: 
Verify proper tension. If loose tighten.

If tension correct, check if belt is shiny from slipping.  If "polished" it might slip even if you have it properly tensioned. If that is the issue, install a new belt.

If this is a mechanical noise from the compressor when the A/C is on, likelihood is you need a new compressor.  If this is a bearing noise when compressor is not engaged, it is likely a clutch bearing which can be replaced separately.

PS, wish we had sense enough to be back up in Angel Fire/Eagle Nest where you not need A/C.

Brett

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Re: Dash AC belt squeal?

Reply #2 – September 01, 2013, 08:08:17 pm

Mike, I recently had a squeal from the AC compressor on a Nissan Pickup. Problem was worn clutch face and that kept the clutch from engaging immediately, when it did stop squealing and engaged it continued to work until clutch didengaged again. Measure the clearance between clutch faces when engaged and then when not engaged, should be no clearance when engaged.
Fix was a new clutch that was available at O'reilleys, had to remove radiator in the PU but on a FT it is easily accessible.
Gary B

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Reply #3 – September 01, 2013, 09:57:38 pm

Thanks Bret, Gary and Dave.    I think given the temp in west texas tomorrow being highs in mid-90s I will just use the house air and not turn on the dash air in case engaging the ac might destroy the belt or such.

Then get home to Nac and see what to do

Yes Bret, sorry to leave Angel Fire/Eagle Nest area but it is time.  The weather is changing, fall is fast approaching.  You can see, feel it.  Not many more early mornings or late afternoons on the pavilion deck. Hope to see you here next year.  You brought couple interesting discussions too.

mike

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Re: Dash AC belt squeal?

Reply #4 – September 02, 2013, 07:59:54 am

I had the same problem for about a year. 
Finally it progressed to the point that it worked for about 10 to 15 minutes and then broke the belt.
Jack Bradshaw diagnosed the issue in about a minute.

When parked and engine door open:

• Turn on your ignition switch
• Turn on your dash A/C switch
• In the back, listen to your A/C fan, rear drivers side on mine

My result:  the fan did not run and the fan ckt breaker was cycling indicating it was overloaded.

Solution: Jack replaced the fan.  It has worked wonderfully all summer. 

My analysis:  without the fan, heat built up in the system making the compressor work harder and harder, putting more and more strain on the belt.

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Re: Dash AC belt squeal?

Reply #5 – September 02, 2013, 10:22:18 am

When my condenser fan quit, the only thing was the duct temp only dropped to 68f,  after replacing the fan, the duct temp dropped to under 50f.
NO SQUEALING/Belt issue, maybe due to keeping the belt at a workable tension.

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Reply #6 – September 02, 2013, 01:15:34 pm

Mike, We had same symptom. Belt was new, but loose. No more problems after tightening.

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Reply #7 – September 02, 2013, 03:23:47 pm

Dash air on our U295 was not cooling as it should. I checked pressures and added one can of R134A. I noticed the high pressure was building more than I expected. The condenser fan was not running. After a bunch of checking and testing, I found two "ragged" relay and socket combinations near the isolator. One relay was for the compressor clutch, the other was for the condenser fan.

The relays were exposed to the elements. I think a pin on each of the relays had corroded through. They were destroyed by the time I got the relays out of the sockets. I replaced sockets and relays. I gave them a generous shot of Corrosion X. Dash air conditioning is working well now.

I considered moving the relays to a more protected location. They appeared to be original equipment and lasted almost 16 years. I decided to leave them in the original location.

If the condenser fan is not running or the compressor is not engaging, you may wish to check the pressure switches and the controlling relays before throwing bucks at the fan motor or the clutch.

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Re: Dash AC belt squeal?

Reply #8 – September 02, 2013, 10:00:57 pm

Oops, good idea JD, had not thought to do that.  Just turned off the dash to get to Vernon, Tx where temp fairly moderate today, I think about 100.  Ran generator and roof ac, did good.  But want the dash to work.  Thanks for the idea.

mike

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Reply #9 – September 03, 2013, 11:38:45 am

I replaces all my self resetting breakers and the condenser fan and the line that runs to it.  It had a couple leaks in it. 

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