No Power to Dash Air/Heater fan

[Mubashir Hayat]

Just returned from a little over a month on the road and my dash air was not cooling. An indicator in the dash showing low pressure illuminated and when I looked it up it indicates low pressure, I guess loss of refrigerant. So preparing to recharge the system picked up the 134a and got everything ready and the dash control will not power on. Was working, fans and heater when I parked. Have checked everyplace I know of for fuses and power breakers etc. There are breakers for the heater fan and ac in the compartment below the driver, they both have power into and out of the breaker, breaker not thrown.  I removed the dash to trace wire to the control unit but did not find any obvious issues there. I unplugged the two wire harness to the compressor to see if something there was causing a break in the power, no difference. One thing I thought curious – checking the side of the harness coming out of the clutch had continuity (closed switch) is that normal? I totally stumped – can anyone offer pointers that could help me find a solution? 2000 Featherlite Vantare,#3207  H3 – does not have bus air Thank you, Ray   Raymond / Andrea and Charlie Prevost H3 Featherlite Vantare #3207 Starting a season of full timing

[Mubashir Hayat]

Does anyone have anidea to help Raymond out?

Per
USAF Retired

[Mubashir Hayat]

On mine there is a breaker that powers up the clutch on the compressor in the electrical compartment in the engine bay. If this breaker is tripped it is possible it could shut down the whole system,on mine it was in the row of breakers on the right .

Richard Wilford and Jill Pankratz
Niverville, Mb, CN.
1999 Featherlite XL 11
Toad 2009 MKX

[Mubashir Hayat]

Thank you, I’ll look in there.

Are you referring to the compartment forward of the engine bay, at the tag on the drivers side?

Thanks again

Ray

Raymond / Andrea and Charlie
Prevost H3 Featherlite Vantare #3207
Starting a season of full timing

[Mubashir Hayat]

Did locate that breaker, it is not thrown. Did throw and reset but no change.

Thank you for the input.

Ray

Raymond / Andrea and Charlie
Prevost H3 Featherlite Vantare #3207
Starting a season of full timing

[Mubashir Hayat]

Ray,

Don’t yell at me, but is the key on?

Tom & Nancy
7 Prevosts Owned

[Mubashir Hayat]

Would never do that – It is a really good question. But yes, both the key and power switch are on. All other related items, radio, seat, alarms etc. that operate normally when the key is on, do so. It’s most bizarre, and confusing. I have always noted that these buses are very finicky and don’t follow the insanity theory, therefore you can do the same thing over again and get a very different result.

This time, I’m just stumped.

Thank you for reminding me that we can – leave things unplugged and off wishing for the on.

Ray

 

Raymond / Andrea and Charlie
Prevost H3 Featherlite Vantare #3207
Starting a season of full timing

[Mubashir Hayat]

Makes me think there is an inline fuse for the control unit somewhere.

When you accessed it behind the dash, did you check to see if there was power to the unit?

Maybe Al will jump in here, he had to replace his on his 2000 Marathon and maybe he remembers if it’s fused.

Tom & Nancy
7 Prevosts Owned

[Mubashir Hayat]

An in-line fuse would have likely been the culprit in my last MH, a country coach, but that did not appear to be the case here. The head unit is a Prevost part. When the dash cover was off I observed 15 or so wires coming from the back of the head unit only exposed for a few inches and then disappeared into the firewall. Could not locate an in-line fuse in the wires from the unit to where it was it became inaccessible.

Per found a troubleshooting guide in the maintenance manual indicating locations to verify power, will be trying that today, and I will post results.

Thank you for your interest, truly appreciate all the input from the community.

I have another idea.

The compressor is a Climate Control Inc. ER2101. At the top of the compressor, at the fill port there is a valve. Does this have to be opened to charge the compressor? Could that be the problem, that the refrigerant is so low it defaults to power block?

Ray

Raymond / Andrea and Charlie
Prevost H3 Featherlite Vantare #3207
Starting a season of full timing

[Mubashir Hayat]

With the low or high pressure light on, the control unit will still function, but compressor will not have power. I’m on my 2nd compressor in 2 years and have seen the warning lights many times.

Tom & Nancy
7 Prevosts Owned

[Mubashir Hayat]

In my case intermit fan on-off operation. With the dash control I looked for something / fuse behind dash and found nothing. Phone calls to Prevost suggested the control regulator behind dash on passenger side. Replaced that with no change. Also suggested check plugs at regulator, blower, dash control as they do shake loose.

In my case the dash unit was defective and replaced solving the problem. Dash units do fail as Prevost admitted making  changes to correct dash control issues. The issue was intermit fan operation. Power was good up to dash control…

Here are pictures I took showing dash unit.

One of the changes was the rear plug-in had been changed on the new dash unit using a short 8 inch plug and play adapter.

AL
Bus Less in KC,MO
3 Marathon’s owned 1- XL 2-H3

[Mubashir Hayat]

In your photo’s I see an in-line fuse. I apparently missed that when I had the dash apart. I believe I’ll go back in today sometime and try to locate a fuse, assuming mine is the same as yours, there should be one.

Thank you for all the information and pictures, very helpful.

Ray

 

Raymond / Andrea and Charlie
Prevost H3 Featherlite Vantare #3207
Starting a season of full timing

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