cbr046 Posted June 15, 2023 Share Posted June 15, 2023 Clip the diode and re-measure resistance. Coils are almost dead shorts until energized (electromagnetic field limits current). You could also connect the clutch directly to a battery (disconnected from anything on the chassis) and test. - bob Link to comment Share on other sites More sharing options...
Agpopp Posted June 19, 2023 Author Share Posted June 19, 2023 Alright, I have a field coil coming from ACparts.com for 50 bucks, so one last help from the group thar I need..... Since I know the polarity of my AC compressor pump is backwards and before I flip the position of the connectors, can someone tell me if the condenser fan on the rear side box should be pulling air in through the door or pushing it out of the door. Let me know on your rigs. This will help me to understand if it was a factory polarity mistake or if someone made an accidental switcheroo on a repair slice somewhere. Thanks! Link to comment Share on other sites More sharing options...
Robert U Posted June 20, 2023 Share Posted June 20, 2023 Condenser fan pulls air in. Bob U 2000 Dip 1 Link to comment Share on other sites More sharing options...
Robert U Posted June 20, 2023 Share Posted June 20, 2023 CORRECTION: I just checked the air flow on condenser fan. It blows air out NOT in. Just checked it on my coach. Hope this did not cause you any problems. CRS Bob U 2000 Dip Link to comment Share on other sites More sharing options...
Agpopp Posted June 20, 2023 Author Share Posted June 20, 2023 25 minutes ago, Robert U said: CORRECTION: I just checked the air flow on condenser fan. It blows air out NOT in. Just checked it on my coach. Hope this did not cause you any problems. CRS Bob U 2000 Dip Didn't get to it yet but thanks! Link to comment Share on other sites More sharing options...
Agpopp Posted June 21, 2023 Author Share Posted June 21, 2023 My condenser fan is definitely pulling in through the door. Anyone else want to check thiers for a tie breaker? Link to comment Share on other sites More sharing options...
Ivan K Posted June 21, 2023 Share Posted June 21, 2023 Often times the shape of fan blades tells you whether it is a pusher or puller but it could be universal too... Wherever colder air comes from or is assisted by airflow while on the move would be my choice. Link to comment Share on other sites More sharing options...
Agpopp Posted June 21, 2023 Author Share Posted June 21, 2023 (edited) Had a ball this afternoon in the closet floor. I was able to do it all without disconnecting the ac lines. I used a lashing strap to a hook in the closet to keep the weight off of it and was able to make it all work. The Advance Auto Parts near me rents the AC clutch puller I needed for free, so that was a bonus. I did cut and splice the connection so the polarity is now correct, and based off the wiring, whoever built that harness simply swapped the terminals when putting into the connector. AC clutch is now functional and operates with the condenser fan with no issues. Only problem now is I have 0 PSI low side and 50 on the high. So maybe there is a blockage or the TXV is plugged. 🤷♂️. Never ends. Edited June 21, 2023 by Agpopp Link to comment Share on other sites More sharing options...
Guest Ray Davis Posted June 21, 2023 Share Posted June 21, 2023 30 minutes ago, Agpopp said: Had a ball this afternoon in the closet floor. I was able to do it all without disconnecting the ac lines. I used a lashing strap to a hook in the closet to keep the weight off of it and was able to make it all work. The Advance Auto Parts near me rents the AC clutch puller I needed for free, so that was a bonus. I did cut and splice the connection so the polarity is now correct, and based off the wiring, whoever built that harness simply swapped the terminals when putting into the connector. AC clutch is now functional and operates with the condenser fan with no issues. Only problem now is I have 0 PSI low side and 50 on the high. So maybe there is a blockage or the TXV is plugged. 🤷♂️. Never ends. Good job, those rear radiators make everything difficult. I'm surprised the clutch will engage with those pressures. You may just need freon. TXV, are you referring to the expansion valve? If so I think a blockage there would lead to a high pressure on the high side or the big number. Has the A/C worked for you before? If it's out of freon it obviously has a leak, you'll need to know if it's a fast or slow leak. A fast leak you will need to repair, however, most RVs leak a little and can be nearly impossible to completely stop so most just add a little as needed. I believe most of our coaches hold approx 4 lbs. Link to comment Share on other sites More sharing options...
Agpopp Posted June 22, 2023 Author Share Posted June 22, 2023 4 hours ago, Ray Davis said: Good job, those rear radiators make everything difficult. I'm surprised the clutch will engage with those pressures. You may just need freon. TXV, are you referring to the expansion valve? If so I think a blockage there would lead to a high pressure on the high side or the big number. Has the A/C worked for you before? If it's out of freon it obviously has a leak, you'll need to know if it's a fast or slow leak. A fast leak you will need to repair, however, most RVs leak a little and can be nearly impossible to completely stop so most just add a little as needed. I believe most of our coaches hold approx 4 lbs. I'm surprised it's running as well and as far as TXV, yes expansion valve is what I'm referring to. The thing is though, I can't get it to suck anything out of the can of 134, and I wonder now if the Schrader valve is plugged up too. Link to comment Share on other sites More sharing options...
Guest Ray Davis Posted June 22, 2023 Share Posted June 22, 2023 Are you certain the clutch is engaging and the compressor is turning? The pressure readings should change at least a little bit when you turn on the compressor. The 134 cans today have a valve built into the top of the can which allows you to use part of a can and save the rest. If your A/C gauges & can adapter are very old you will not be able to get the freon from the can. That may be why you can't get any freon to go in. There is an adapter that will allow you to still use your old equip, I have seen them at Walmart, auto parts stores should have them too. Link to comment Share on other sites More sharing options...
cbr046 Posted June 22, 2023 Share Posted June 22, 2023 If the system is low enough the compressor won't engage. There's a safety switch, probably near the schrader valves, where you can short the connector and the clutch will engage. Give it a minute (or two). If you're not pulling freon out of the can by then (can will get frosty cold) there's a problem. You can hold the can upside down for faster delivery with a low system. Any freon should "boil off" before it gets to the compressor (your schrader valves are up near the front, right?). By the time you empty one 12oz can you might be able to re-connect the switch. Running for an extended time with no freon will toast the compressor. Continuously filling liquid freon (can upside down) can hydraulic lock the compressor. An empty system can take . . . . 40 oz? Several cans, anyway. - bob Link to comment Share on other sites More sharing options...
Ivan K Posted June 22, 2023 Share Posted June 22, 2023 If you suspect the Schrader valve, what happens when you push the center pin? Could be plugged if someone used a leak sealer but the valves can be replaced without emptying the system. 1 Link to comment Share on other sites More sharing options...
Agpopp Posted June 22, 2023 Author Share Posted June 22, 2023 Clutch is operating and engaging when commanded by the dash switch, so the low pressure switch must be making contact. I need to spend some time with the gauges to determine what is going on. I'm leaning towards a blockage but can't be sure until I look at that low side port again. Link to comment Share on other sites More sharing options...
Agpopp Posted June 25, 2023 Author Share Posted June 25, 2023 (edited) AC is up and running! The low side port was stuck closed and it took pushing on it with a pick to pop it open. I put my gauges on it for ambient and had 40 on both sides, so it was really low, but 27 is the cutoff I believe for the low pressure switch. I was able to get almost 3 12 oz. cans in, and it holds 34 so just about empty. I now had 30 low, 140 high at 70 degrees ambient with the idle at 1250, little less at idle. So for 50 bucks and a little trouble shooting I was able to rescue what the PO spent 2600 on. Time will tell how fast it leaks out, but for now it's cold. 🥶. I did bench test the old coil and found it was the diode that was shorted (I assume, because its packaged and not serviceable). After cutting all the wires except the coil leads I was able to ohm out resistance instead of 0 with the diode package connected. The guy at ACPARTS.COM did say they used to solder in a new diode for repair but no longer could after Sanden changed the design to prevent such repairs (nice). If you need anything I strongly suggest calling them and asking for Richard. Very knowledgeable guy, and I know I've mentioned him already. The root cause for the failure was Monacos error in wiring that plug, and who knows how many compressors it took out in this rigs life. So for now, case closed. Edited June 25, 2023 by Agpopp More info 1 Link to comment Share on other sites More sharing options...
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