11-28-2016, 01:10 PM
Richard, I was surprised by that also so I made the same check on the front AC and found the same condition. The front unit operates correctly so I concluded that the high/low system must shut down #2 compressor when set on low.
Another unexpected surprise today. The rear AC started operating on low, that is the low speed fan and #1 compressor. On high, the fan went to a faster speed and #2 compressor started along with #1. This is the first time that I can recall it ever operating at all on low.
On both the front and rear units, I checked the volts going from the board to the compressors. It was 122 volts in all cases, even when I reversed the compressor connections. On low, compressor #1 is 122, #2 -0-, and on high both are at 122. However, there was something I did not expect. The common for compressor #2 is not connected to the bundled common which #1 is connected to. I think this tells me that when I install the heavy duty relays, I should keep the common for #2 separate.
As I have stated, the front AC operates normally. On low, #1 draws 8 amps, #2 -0-, and on high both draw 8 amps. Not so for the back AC. With compressor connected normally as they were originally installed, #1 draws 4 amps on low and 5 amps. on high with #2 drawing 7 amps. When I reverse the compressor connections, the amps are also reversed. On high or low, #1 draws 7 amps, and #2 draws 4 amps.
Now as to cooling, with the coach at 65 degrees inside, the AC exhaust temp was 57 degrees with only #1 operating at 4 amps. But when I reversed the compressor connections, there seemed to be no cooling even though the compressor was drawing 7 amps.
With 122 volts at the compressor connections under all circumstances, compressor #1 draws 4 amps normally and 7 when the connections are reversed, could something in the board cause the drop in amps? Looks like it is time to install the front board in the rear AC of ship the board off to Flight Systems, Inc. for service.
Richard, I feel guilty that you are spending so much time on this, but you have taught me a lot.
Another unexpected surprise today. The rear AC started operating on low, that is the low speed fan and #1 compressor. On high, the fan went to a faster speed and #2 compressor started along with #1. This is the first time that I can recall it ever operating at all on low.
On both the front and rear units, I checked the volts going from the board to the compressors. It was 122 volts in all cases, even when I reversed the compressor connections. On low, compressor #1 is 122, #2 -0-, and on high both are at 122. However, there was something I did not expect. The common for compressor #2 is not connected to the bundled common which #1 is connected to. I think this tells me that when I install the heavy duty relays, I should keep the common for #2 separate.
As I have stated, the front AC operates normally. On low, #1 draws 8 amps, #2 -0-, and on high both draw 8 amps. Not so for the back AC. With compressor connected normally as they were originally installed, #1 draws 4 amps on low and 5 amps. on high with #2 drawing 7 amps. When I reverse the compressor connections, the amps are also reversed. On high or low, #1 draws 7 amps, and #2 draws 4 amps.
Now as to cooling, with the coach at 65 degrees inside, the AC exhaust temp was 57 degrees with only #1 operating at 4 amps. But when I reversed the compressor connections, there seemed to be no cooling even though the compressor was drawing 7 amps.
With 122 volts at the compressor connections under all circumstances, compressor #1 draws 4 amps normally and 7 when the connections are reversed, could something in the board cause the drop in amps? Looks like it is time to install the front board in the rear AC of ship the board off to Flight Systems, Inc. for service.
Richard, I feel guilty that you are spending so much time on this, but you have taught me a lot.
2001 Newell #579
tow a Honda Odyssey
fun car: 1935 Mercedes 500K replica