Drag Racing Discussions > Tow Vehicles

It is getting hot at races, poor time for A/C to fail


When we went to the race at Norwalk we had a number of systems that failed on the Motor Home. One was the Refrigerator (the gas fired side, the electric ran fine the whole weekend) and that has been fixed and a video produced on that.

Another failure was the step motor (again) that has been replaced and video produced.

We had the line between the transfer pump and the injector pump fail (it wore through due to a rub point on an old clamp (that was documented here).

Finial was the front A/C unit stopped producing cool air. The fan ran, and the compressor ran, but it produced no cool air (on a hot weekend, seem like more and more race weekends are HOT). We were fortunate that we have ceiling ducts. We closed the ones in the rear and left the ones in the front open. This pumped the cool air from the rear unit to the front ducts.

I could not find much information on the process of swapping out the A/C unit. On big question was how to get the unit off the roof and the new on the roof. I was reminded here of a video produced by Terry in his thread Total Rebuild on how he got his A/C unit up

As of today I have yet to speak with any A/C manufactures, left messages (fill out forms online but was never contacted). I ordered a Coleman A/C unit Mach 15 48204C866 as a guess and pretty much in the dark. I thought I had a model 7333C8864 which is a 13,500 BTA unit based on the documentation that came with the coach, wanted to upgrade to 15,000, the A/C unit.

There is very little guidance on the pieces and process needed to do the swap. There are suggestions that you need the A/C unit, a new control unit, and a new grill as the old ones are not supposed to fit. In my case I only needed the A/C unit, the old control model works fine and the grill did not need replacing, in fact had I ordered it, it would not have fit.

The unit I received looks identical to the unit I am replacing (compressor, condenser, plumbing, the old cover fits on the new unit), with a few exceptions. The mounting bolt holes are in a different location, old mounting bolts are 5/16 and the new ones are inch, the intake and exhaust ports are in the same location but slightly different shapes (I attribute these changes to change made to the unit over the years).

This long video is the process from the new unit sitting on the floor in the garage to testing the temperatures produced from the new unit.

Nice video. We're having to do the same job on our trailer. How do you like the Coleman unit?

I have a smaller Carrier unit on the top of my 28 foot enclosed race trailer that I think does a better job.

I went with the Coleman because that was what was on the Motor Home and was hoping for a direct fit.

I would have expected more cooling from a 15,000 BTU unit, but it does the job.

Thanks! What BTU you using on the trailer? I have a 32' with a single unit.

I do not remember, but believe it is 13,500

This is not the 28 foot trailer but is the unit on top of the trailer


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