Ambulance medium duty. The airconditioner secret. How does it work?????????

[Ozrockrat]

Anybody know the secret between the front and back AC setting to actually get them to work.

OK I have not had any AC in my truck for 3 years. Not really a problem until the summer in Phoenix but I am usually OK with 2-60 AC in the most part (2 windows down and 60 MPH). But I am getting old and soft and I did some digging around and found that both my systems are charged and both compressors will kickin and provide cold air if I put 12v on the clutch.

I do remember somewhere on expo the mention of the back system controlling the front or such like. Since its 100 outside I figured I would ask instead of chasing wiring diagrams and wiring.

Anyone with any ideas.

 

[rossvtaylor]

I'll be watching this thread, too! Thanks for asking the question. Our rear air conditioning is not getting cold and I'm not sure what the issue is, yet. We haven't had time to dig into it, yet, but I just assumed we needed a recharge. I do have a panel switch up front which has to be on, but even with that the rear's not cooling.

 

[tgreening]

Mine is just an E-series so the operation might not transfer to your rig, but on mine front and rear a/c are controlled separately. There's a switch in the cab for enabling heat/a.c. in the module, but once enabled the controls for heating/cooling temp and fan speeds are all in the module.

 

[cjken]

Mine is controlled the same way
Switch up front then fan and temp controls in back.

 

[gringorick]

Mine operates the same. Both front and back use the same compressor, but the fan on the back unit will not work until the Patient AC switch is turned on.

The rear AC operates independent of the cab AC.I do not have to operate the cab AC in order to get cold air in the back.

 

[Ozrockrat]

Ok I did not find out how it is supposed to work but I now have the cab one working.

Combination of removing where the compressor clutch wire looped out to somewhere and actually getting a correct fuse panel diagram which showed I had one fuse missing. Gas was low and little cans suck for topping up a reasonable size system.

So in summary there is an interlock between the cab AC and the Box AC in some ambulances. But there is no indication of it in either the body builder wiring diagrams or the diagrams that came with the box.