Saga of the Coleman-Mach Basement A/C

[kkocan72]

Originally Posted by Jim_HiTek

Well, no, a 1--- means OPEN CIRCUIT. Not a short. So if you're looking for a short, you're looking for the wrong thing. An open would be a wire that's fallen off a terminal or out of a connector.

Take the compressor's small cover off and take a picture. Show it here.

Gotcha. Since I have not done much with my MM when working with resistance this part is a bit new to me. I was thinking it would read a 1 if the two leads went into the compressor then it was shorted to the ground. I guess to test for compressor shorted to ground I would ground one of the leads from my MM and then touch the others to the 3 wires going into the compressor and hope I see a "1" for open line correct? Or when I take the AC out do the same with the actual terminals on the compressor and make sure the MM reads "1" when having one probe on something metal on the frame and one on the connection(s).

Would an open circuit though be causing my breaker to keep shorting when power is applied to compressor #2? I guess if I have a loose connection/broken wire it could, right?

[Jim_HiTek]

Take the 2 MM leads and short them together. That will show you the reading for a short circuit. Remember that reading because that's the resistance of the leads themselves and sometimes you want to be able to ignore it.

Games getting exciting so I'll be back tomorrow.

[kkocan72]

Originally Posted by Wild Card

Check each winding/terminal @compressor to ground..

Yeah that will be the first thing I do when I pull the AC out of the basement, hopefully this weekend. Hoping I find a "1" indicating open and I don't have a short to ground in the compressor.

[kkocan72]

Originally Posted by Jim_HiTek

Take the 2 MM leads and short them together. That will show you the reading for a short circuit. Remember that reading because that's the resistance of the leads themselves and sometimes you want to be able to ignore it.

Games getting exciting so I'll be back tomorrow.

Well looks like I need a new compressor. Took the AC unit out, probably the worst thing was dealing with a couple of seized up screws that had to be drilled out. Took two of us quite a bit to get it out but once we did set it on a couple buckets with some boards to stabilize.


My neighbor came to check out what I'm doing. He's a retired electrician and new exactly what I was talking about when it came to ACs and compressor problems so he got involved and helped troubleshoot.

First thing we did was take the cover off the lead terminal at the compressor. Didn't see any signs of a short or any issues.


Next thing we did was test the terminals by connecting them to each other and found all had resistance; then we checked each one to ground and all were good so it does not appear the compressor has a short to ground. We tested the 3 leads at the top and also checked the thermal protector. We also took the flat black plug thing off and tested it (can't see it in the pictures). To make sure the leads coming from the caps/relays to the compressor by checking them from both ends and all were good and had continuity. After doing all that, and watching the unit try to cycle up a few times while we had it out and all the covers off, my neighbor told me it is most likely a bad/seized compressor that is pulling too many amps trying to start up.

Looks like I'll be searching for a new compressor so I took some pics and will be reaching out to some local HVAC guys to see if they want to work on the unit.


While I have it out I'll oil up the blowers but everything else looked good. Squirel cages all looked good, bearings were smooth and other than oiling and cleaning things up I'll probably put it back in and just deal with 1 compressor for the rest of the season (unless someone can get to it quickly).

If anyone has any other ideas on what it may be I'd be interested in hearing them, but doesn't look good as of now.

[BCam]

I'm no expert but I have an unresolved issue with my basement air so I've read extensively on the subject over the past two or three years.

I've read that these units are very similar, if not almost identical, to Coleman units used for mobile homes. With this information, along with the information that the unit is out of your MH, you may be able to find someone. You might want to be sneaky by getting the model info on the mobile home units and asking the HVAC if they repair them. If yes, then ask about your unit.

Unfortunately, although replacement units are available, they've pretty much doubled in price over the past two or three years. At one point they were about $2,200 or so but now they're over $4,000 and as high as $5,900. At $2,200, I'd have suggested DIY replacement but at the current price, probably not. On the other hand, if the repair cost is astronomical as well, it's something to consider. I've read several threads where others have spent $800 or more in unsuccessful repairs only to replace the unit down the line (this was when a replacement unit was in the $2K range). At that time, my thought was that I'd rather pay $2K for a new unit than $1K for repair.

While it's out, you might want to consider replacing the squirrel cage fan (replacements should be available) before it's bearings go out along with any other easily replaceable parts, including new crimp-on wire terminals if there's enough slack in the wires.

Should you decide to go the replacement route, your exact model may not be listed but it should be cross-referenced. The most commonly available replacement model seems to be 46515-811 that cross-references to a number of older models. From what I've read, the major issue is for those who have a a top-venting model, which require some modification of the replacement, but you don't have that issue:

https://www.amazon.com/Coleman-46515.../dp/B01MG1GSFC

[MrMark52]

Any residential HVAC guy can do the replacement - it’s just a matter of finding someone who will do it.

Note the system is R22 - by the time he recovers the refrigerant, replaces the compressor, purges and evacuates the system before weighing the correct charge in - you might be looking at about the same $ as a new unit (assuming you can get a new unit in a reasonable amount time).
If you can get someone to do it - make sure they properly use the process tube to do the evacuation and charge, and that they DO NOT leave Schrader valves on the system.

[BCam]

This may be crazy, but have you tried giving the offending compressor a good, but not to violent, whack with a rubber mallet?

[kkocan72]

Originally Posted by BCam

This may be crazy, but have you tried giving the offending compressor a good, but not to violent, whack with a rubber mallet?

You know I was thinking the same thing, lol. I have a couple friends that run small HVAC companies. I'm going to take them some pictures Monday and ask what they would think about working on it if I had it out of the unit, ready to go and I buy the compressor.

[Jim_HiTek]

Originally Posted by MrMark52

Any residential HVAC guy can do the replacement - it’s just a matter of finding someone who will do it.

Note the system is R22 - by the time he recovers the refrigerant, replaces the compressor, purges and evacuates the system before weighing the correct charge in - you might be looking at about the same $ as a new unit (assuming you can get a new unit in a reasonable amount time).
If you can get someone to do it - make sure they properly use the process tube to do the evacuation and charge, and that they DO NOT leave Schrader valves on the system.

DIY'ers don't need to use R22 ($45/lb in bulk so the shop would add onto that price). They can use the equivalent amount of Enviro-Safe coolant instead of any Freon.

If I recall correctly, a 6oz can ($8/can) is equiv to 16oz of Freon. A DIY'er doesn't need a compressor either. Just vent to the atmosphere (legal to do so...only HVAC shops are required to recover the R22), or invite a shop to recover it free, add the Enviro-Safe (propane/butane mix), some oil, some stop leak, and boom, done. (More to it than that as the oil is added and the compressor is switched on so it can suck the mixture into the system, then add the coolant one can at a time). The molecules of the coolant are large so a Schroeder valve is okay to use. For a very small $$ amount, very little time, and just as much cooling.

I have it in my dash AC system now (44oz of R-134a I didn't need to buy) and it's been working great for a couple years and a few thousand miles AND the madding slow leak that use to plague the system is now undetectable.

I've already decided to replace the compressor myself if one of them ever goes out in my Coleman, and use the Enviro-Safe refrigerant. My guess is that it will cost right around $600 (including the $450 for the compressor) to change out 1 compressor from the Coleman Heatpump using Enviro-Safe coolant. BTW, eBay carries it.

[MrMark52]

Originally Posted by Jim_HiTek

DIY'ers don't need to use R22 ($45/lb in bulk so the shop would add onto that price). They can use the equivalent amount of Enviro-Safe coolant instead of any Freon.

If I recall correctly, a 6oz can ($8/can) is equiv to 16oz of Freon. A DIY'er doesn't need a compressor either. Just vent to the atmosphere (legal to do so...only HVAC shops are required to recover the R22), or invite a shop to recover it free, add the Enviro-Safe (propane/butane mix), some oil, some stop leak, and boom, done. (More to it than that as the oil is added and the compressor is switched on so it can suck the mixture into the system, then add the coolant one can at a time). The molecules of the coolant are large so a Schroeder valve is okay to use. For a very small $$ amount, very little time, and just as much cooling.

I have it in my dash AC system now (44oz of R-134a I didn't need to buy) and it's been working great for a couple years and a few thousand miles AND the madding slow leak that use to plague the system is now undetectable.

I've already decided to replace the compressor myself if one of them ever goes out in my Coleman, and use the Enviro-Safe refrigerant. My guess is that it will cost right around $600 (including the $450 for the compressor) to change out 1 compressor from the Coleman Heatpump using Enviro-Safe coolant. BTW, eBay carries it.

Sorry - I’ll just say that I’m glad I will never need to use your experience to service any of my equipment. Too many things awry with your stated experience for my liking.

[Jim_HiTek]

Originally Posted by Jim_HiTek

SNIP: "If I recall correctly"
SNIP

No one said you have to follow anyone else's advice, ever. I like saving ~$6,000 for repairs to my AC and have it work well into the future so I think it's okay to attempt repairs using the method mentioned if I ever need to. There's little magic to HVAC, due diligence and due care is all it takes.

You have some specific criticism of the Enviro-Safe products? Or the fact that I used it on my dash air? They aren't the only ones supplying it, btw. And their products come with instructions that I haven't read in 2 years so my off-the-cuff explanation above might be a bit off, that's why people should read instructions. And if I find I need to hire a HVAC tech to replace a compressor, I'll do so. I ain't proud.

[kkocan72]

Originally Posted by MrMark52

Any residential HVAC guy can do the replacement - it’s just a matter of finding someone who will do it.

Note the system is R22 - by the time he recovers the refrigerant, replaces the compressor, purges and evacuates the system before weighing the correct charge in - you might be looking at about the same $ as a new unit (assuming you can get a new unit in a reasonable amount time).
If you can get someone to do it - make sure they properly use the process tube to do the evacuation and charge, and that they DO NOT leave Schrader valves on the system.

We had some work done late last fall and the plumbing/HVAC guy has not been able to get a crew back to finish the retaining wall they had to take out. They have said their earthwork crew is just really backed up. I may call the owner (he's doing some work for me at my work place as well) and see if I tell him to not worry about the landscaping and finish it myself if he will send a tech over to swap out my compressor (if I pull the unit out and have it waiting for them). The landscaping is no big deal and I can make my kids help me put the wall back together.

If I can swing a deal with him I may just order a new compressor this week.

[kkocan72]

Originally Posted by BCam

I'm no expert but I have an unresolved issue with my basement air so I've read extensively on the subject over the past two or three years.

I've read that these units are very similar, if not almost identical, to Coleman units used for mobile homes. With this information, along with the information that the unit is out of your MH, you may be able to find someone. You might want to be sneaky by getting the model info on the mobile home units and asking the HVAC if they repair them. If yes, then ask about your unit.

Unfortunately, although replacement units are available, they've pretty much doubled in price over the past two or three years. At one point they were about $2,200 or so but now they're over $4,000 and as high as $5,900. At $2,200, I'd have suggested DIY replacement but at the current price, probably not. On the other hand, if the repair cost is astronomical as well, it's something to consider. I've read several threads where others have spent $800 or more in unsuccessful repairs only to replace the unit down the line (this was when a replacement unit was in the $2K range). At that time, my thought was that I'd rather pay $2K for a new unit than $1K for repair.

While it's out, you might want to consider replacing the squirrel cage fan (replacements should be available) before it's bearings go out along with any other easily replaceable parts, including new crimp-on wire terminals if there's enough slack in the wires.

Should you decide to go the replacement route, your exact model may not be listed but it should be cross-referenced. The most commonly available replacement model seems to be 46515-811 that cross-references to a number of older models. From what I've read, the major issue is for those who have a a top-venting model, which require some modification of the replacement, but you don't have that issue:

https://www.amazon.com/Coleman-46515.../dp/B01MG1GSFC

Yeah new units are $4k plus. I've already been shopping! But I'm trying to work a deal with a local plumber/HVAC that still has to finish some landscaping on my house from a job late last fall.

We did look at the blower motors, bearings etc... All are in great shape, no wobble, bearing feel super smooth on both blower motors. I oiled the ports for the cages while I had it open, cleaned everything up, cleaned the fins at the intake and had to put it back in the rig today with only 1 compressor functioning. I can't leave it parked in my driveway more than a day or two without the neighbor complaining. But now that I know how to pull it out I can probably do so in 20 min or less. So if I can get my HVAC friend to swap compressors I may just buy a new compressor and make arrangements with him.

[Seacrazy]

Well, similar problem to KKOCAN, I’ve pulled my Coleman AC out. Called all around, and HVAC people in Seattle area DO NOT want to touch them, in or out of the coach. An HVAC truck was near my house, I called them and they came out this morning. He steps out of his truck, looks at the motorhome with AC out and says “we don’t work on those”. Out of pity seeing my reaction, he said he would take a quick look. He asked what was going on, popped the top, etc. long story short, said compressor 2 is shot based on seeing high amps exceeding LRA and compressor 1 is low on refrigerant probably if not cooling at all. He said he’s got r22, but strongly recommended to replace unit, even at $4k.

So, regardless of what I decide, I have question about my elbow duct. I tried to be careful, but when removing ac and wiring, the elbow separated from the higher up straight vent and I broke a small piece of styrofoam piece of duct,,,,,. See pic.
What is best way to repair?
- probably install ac back in coach and attach vent before retaping elbow? (But less room to work once ac and elbow back on.)
- soap & water to clean dirt & dust first?
- wrap with Venture ? Tape?
- Home Depot didn’t have Venture, but had Nashua Extreme weather tape at $27.58/ roll, is that same?
- is there anything else I could add to wrap around too? That AC blows quite a bit of current up that vent, plus the weather elements it sees.