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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: chazwood on August 14, 2009, 07:48:06 AM

Title: thermostat question
Post by: chazwood on August 14, 2009, 07:48:06 AM
Hey all,
My 82 MCI thermostat for the over the road air/heat seems to wink off and on spasmodically, so much so, the bus never gets cooled down. Any way to bypass the temp control and let the compressor just run continuous?
(I had the freon checked recently and it's fine)
The dummy light on the dash goes off and on every 15-30 seconds no matter where I set it.
Thanks,
Chaz.
Title: Re: thermostat question
Post by: Len Silva on August 14, 2009, 08:53:54 AM
Chaz,

I can't offer specific advice except to find and fix the problem.. It may not be the thermostat.  The problem with bypassing is that you may lose the protections offered by the various circuits involved.  You could have high head pressures or low freon and never know it until you do major damage.

If you have wiring diagrams, it should be fairly simple to locate where the intermittent fault is. 

If you know for sure that it is the thermostat then temporally bypassing it should be OK.
Title: Re: thermostat question
Post by: chazwood on August 14, 2009, 09:06:24 AM
Well, I was just poking around the bus and running the air for a while, and it seems to my uneducated self that the metal-loopy-coil-pipes on the side of the evaporator should be cold to the touch......they ain't.

Seems like no freon is moving.
Title: Re: thermostat question
Post by: Nick Badame Refrig/ACC on August 14, 2009, 03:19:08 PM
Hi Chaz,

Check your condencer coil in the side compartment for dirt build up, or the fan may not be running at full speed..

When the light on the dash is lit, it usually means the high pressure switch is tripping or the compressor unloaders

are opening and letting the compressor free wheel.

Let us know
Nick-