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RVThere · 06-21-2016, 10:12 AM

So by using some of the info on this great forum and my own examination, I was able to get the side sheet metal panel off of my basement air unit without disconnecting from the air plenum elbow or pulling the unit out.

Now I have full access to the two compressors but can't find any port to recharge the AC. Can anyone help give me some direction?

Unit is a Coleman-Mach 6538-871

View of the tops of compressors:

View of unit from outside:

**Lt Dan** · 06-21-2016, 03:31 PM

Great job getting this far, but as far as I know there is no charging port in the refrigerant lines. They are a sealed system, just like the roof units. You can use an add on port that will pierce the tubing, but that may be just asking for leaks. A service tech could probably cut the line an solder in a port, but that's pretty complicated.

Fred and Bonnie · 06-21-2016, 04:25 PM

Agree with Lt Dan, I believe your best bet would be to contact a residential HVAC company, they have the experience.

Fred

RVThere · 06-21-2016, 05:41 PM

Fred and Lt Dan - Thanks for your input, totally agree.

Once I got the panel off, I could confirm that Compressor #2 was not running. When the circuit board would call for #2 to start, it seemed like the whole system slowed down but would recover without Compressor #2 starting. I first checked the start capacitor and it was fine. Same with the run capacitor.

There is also a red LED on the circuit board that indicates when the board is calling for Compressor #2 to run. It illuminates a few minutes after the AC turns on if the temp is set low enough. Red LED was on.

I studied the schematic on the electrical access panel and did a little more research. Compressor #2 runs through the Intellitec system which shuts down the 12 volts to the power relay if its managing only 30 amps of coach input power.

So I checked the relays for #1 and #2 compressors. #1 was getting high voltage fine but no power was being passed through the relay to #2 compressor.

Next I checked the 12 volt signal going to the relay via the Intellitec and it was dead. Using my PowerProbe (if you don't have one of these tools, BUY ONE!), I applied 12 volts to the relay and BINGO, Compressor 2 started!

Since we'll be plugged into 50 amps or running the genset, I pulled out the wire (white with black stripe) going to the Intellitec and plugged the orange wire from the relay directly to the circuit board. I'll mess with the Intellitec when I have time.

Ran the AC for a few hours and the air was much colder coming out of the roof vents.

We'll be doing a NJ to CA to NM to TX to MS to FL Keys trip in two weeks. I was very concerned that we'd be sweltering in the coach while driving through the desert. For now, we're cool!