Basement AC not blowing cold air.

[tommymsw]

As fate would have it, 10 days before I leave for AZ, my AC seems to have stopped working. Aside from the air not being cold, there is no puddle of water under the AC when it runs. (I am in NH and it is VERY humid)

I assume this means the compressor is not running (either of them?). However, I have only been able to test this running on my generator. If the generator is not pushing the right amount of Amps, is it possible THAT is the problem? The air blows fine, but seems to be blowing LESS strong? (Could be my imagination though)

I get 120v from the outlets so I know the gennie is working, but maybe it is not trowing enough amps?

I do not have a couple thousand to have it fixed and still make my trip. I am looking to diagnose and fix it myself if possible.

I can bring it to an RV park, plug it in and test it, but I want to make sure that is the right option before I waste any money.

[Cooperhawk]

Right now ours is in a shop and the AC had quit working. They called a bit ago and said that it's probably a capacitor or switch that is bad. It could be some thing simple like that for yours as well. Our weather has been very very humid as well.

[jerichorick]

Originally Posted by tommymsw

As fate would have it, 10 days before I leave for AZ, my AC seems to have stopped working. Aside from the air not being cold, there is no puddle of water under the AC when it runs. (I am in NH and it is VERY humid)

I assume this means the compressor is not running (either of them?). However, I have only been able to test this running on my generator. If the generator is not pushing the right amount of Amps, is it possible THAT is the problem? The air blows fine, but seems to be blowing LESS strong? (Could be my imagination though)

I get 120v from the outlets so I know the gennie is working, but maybe it is not trowing enough amps?

I do not have a couple thousand to have it fixed and still make my trip. I am looking to diagnose and fix it myself if possible.

I can bring it to an RV park, plug it in and test it, but I want to make sure that is the right option before I waste any money.

I am a bit confused with your post. Water usually means cooling. Where "under" do you see the water? On the ground?


How many amps are you drawing when the A/C is running? You may not have a meter on board to read. Bummer. Need to put a clamp meter on the lead in the ATS. This can be a problem if you don't have the know-how.


With the A/C running, walk to the back of the coach and look for condensation on the skin. The plenum going from the basement air to the ceiling has a history of coming apart. Happend in my old coach. It is a real pain to reattach.


I take it the filter is good? Use a flashlight to inspect the cooling coil behind the filter, You should be able to look down to it. Make certain it is clean. You can buy cleaner to spray on it and blow it off with compressed air.


Let us know what you find.
Rick

[tommymsw]

Originally Posted by jerichorick

I am a bit confused with your post. Water usually means cooling. Where "under" do you see the water? On the ground?


How many amps are you drawing when the A/C is running? You may not have a meter on board to read. Bummer. Need to put a clamp meter on the lead in the ATS. This can be a problem if you don't have the know-how.


With the A/C running, walk to the back of the coach and look for condensation on the skin. The plenum going from the basement air to the ceiling has a history of coming apart. Happend in my old coach. It is a real pain to reattach.


I take it the filter is good? Use a flashlight to inspect the cooling coil behind the filter, You should be able to look down to it. Make certain it is clean. You can buy cleaner to spray on it and blow it off with compressed air.


Let us know what you find.
Rick

What I mean by "water on the ground" is that usually in an auto, when the AC is running, water will drip onto the ground... Same with my RV. Since there is no water dripping from the AC, I can assume the compressor is not running. If it were running but the air line had become disconnected, i would still expect to see water coming out of the unit. I would expect to see water even if the filter was not clean (it would work LESS well, but at least work a little).

No water to me, means the compressor is not running. I am only assuming this, but i think it is a fair assumption.

I have no way of checking the amp draw.

[tommymsw]

My generator IS acting strange. It does not seem to idle up when it is supposed to. If I have the AC "fan" on LOW and then switch to HIGH, there is mo difference in blow. If I turn up the idle on the generator manually, then I get stronger blow on HIGH than on LOW. So I think that may mean it is not sending enough power.

I will have to take the RV to a park and plug it in to test if the AC works off of shore. I wish I had a place near by to plug it and test it.

[jerichorick]

Originally Posted by tommymsw

My generator IS acting strange. It does not seem to idle up when it is supposed to. If I have the AC "fan" on LOW and then switch to HIGH, there is mo difference in blow. If I turn up the idle on the generator manually, then I get stronger blow on HIGH than on LOW. So I think that may mean it is not sending enough power.

I will have to take the RV to a park and plug it in to test if the AC works off of shore. I wish I had a place near by to plug it and test it.

Plug in a heater, flat iron, hair dryer, etc and see if the generator reves up then. If so, the generator is ok.
Can you get the A/C out of the coach. I did it on my last rig. It was not easy. After 18 years I am certain you will find a bad start or run capacitor or other problems. Get a residential HVAC service guy to look at it. They are best qualified and you don't have to move the rig.
(PS: Raised in Berlin )

[BobC]

Here's a link to a page with a lot of good info on the basement air conditioner, including detailed instructions for removal so you can get at the capacitors, fan, etc. It doesn't look like that big of a job as long as you know what screws to remove and have it well supported so you can just slide it out.

https://sites.google.com/site/billmarie2008/

I think that a plywood box or 2 x 4 frame on a Harbor Freight furniture dolly would work to support and slide it out as long as you're on a level surface. I think I'd use several wooden wedges to fine tune the height of my "cart".

It's not unlike a large window mounted A/C.

My squirrel cage fan rattles a little until the A/C has been running a while so I'm thinking about replacing it. When I do, I'm going to replace the capacitors as well. Electrolytic capacitors have a limited life span and aren't that expensive or difficult to replace. If they show signs of leakage or swelling, they definitely need replacement but, even if they look OK, you might as well replace them if you're that far into things.

If you do remove the unit to replace the capacitors (do them all), you might as well replace the squirrel cage fan with a new, plastic replacement as well, since your existing bearings are likely to eventually fail.

[fnjrrd]

I have an 03 Suncruiser 35U. Had a similar problem. On some units there is an electrical access door to the left of the unit as you're looking at it. Of course this is with the large outer door on the coach opened revealing the complete unit. I say some because that's what I read on this forum and as luck had it mine had the access door. It was obvious that one of the capacitors was toast. Less than $10 later (in stock at a local electrical supply store) it was good to go. (easy access and easy to change out) That was a year ago (knock wood) still working fine. Good luck.

[BobC]

Originally Posted by fnjrrd

I have an 03 Suncruiser 35U. Had a similar problem. On some units there is an electrical access door to the left of the unit as you're looking at it. Of course this is with the large outer door on the coach opened revealing the complete unit. I say some because that's what I read on this forum and as luck had it mine had the access door. It was obvious that one of the capacitors was toast. Less than $10 later (in stock at a local electrical supply store) it was good to go. (easy access and easy to change out) That was a year ago (knock wood) still working fine. Good luck.

Thanks for the info, I hope my 2002 35U has that access door! I'll check it out.

[tommymsw]

Originally Posted by jerichorick

Plug in a heater, flat iron, hair dryer, etc and see if the generator reves up then. If so, the generator is ok.
Can you get the A/C out of the coach. I did it on my last rig. It was not easy. After 18 years I am certain you will find a bad start or run capacitor or other problems. Get a residential HVAC service guy to look at it. They are best qualified and you don't have to move the rig.
(PS: Raised in Berlin )

That is some good thinking. I will try the heater trick and see.

[tommymsw]

So the generator for SURE is not working right. I ran the microwave on same water for about 3 minutes. Not only sis the generator not rev up, but the water was only slightly warm. My guess is that the generator is not revving up and supplying enough energy to get the compressors on the AC working.

my wild guess is the circuit board. I am assuming that part of the generator is electric and not mechanical. I will start a new thread I suppose.

[silvertip101]

Yes, I lost a capacitor on cooling compressor, last month lost capacitor on heat pump die. Best visual is you may see burnt area

[BobC]

Originally Posted by BobC

Thanks for the info, I hope my 2002 35U has that access door! I'll check it out.

Good news, I do have the access door and it appears that one of my "run" capacitors has been replaced, but not the other. The start capacitors look like they're original. I may just replace all of them, but, since access is so easy, I think I'll sleep on it.

I found this post on another forum that is helpful, including amperages:

Basement central air conditioner

I'll also check the ducting while I'm at it and re-seal with heavy duty all-weather aluminum duct tape if necessary.

[BobC]

Just to be safe I ordered two starting and two running capacitors. I think I may just install what I need now and keep the rest in reserve in case I have a future failure. I know #1 works but I'm not sure if #2's issue is the starting cap, running cap or something else.

Number 2 sounds like it's trying to kick in but doesn't run. It could be that the starting cap isn't putting out enough of a kick to start it or it could be the run cap has failed. Hopefully it's not the compressor itself. Amazon tells me they should be here 7/25 -7/27, I'll let you know how it all turns out. I know I could probably narrow it down with some troubleshooting but this will be quicker and it's hot outside. There are signs of leakage under the #2 run cap but it's the one I thought looked like a replacement so it could be from an old leak. I'll start with it. I'll test it with my generator so I don't trip my 20A house breaker.

Keep your fingers crossed.

[tommymsw]

I have taken the AC regulator out of the generator. It appears fine, but it MUST be my problem. I wish more people had had a similar problem so I could be sure... the Replacement part is $300.

[BobC]

I'm not sure what generator you have, but I found this youtube video on testing an Onan regulator. I would think the same technique would work on other models:

https://www.youtube.com/watch?v=qrUfjyi-Znc

There are several videos on trouble shooting and repair of generators. You might want to check these out before spending $300.

[tommymsw]

Originally Posted by BobC

I'm not sure what generator you have, but I found this youtube video on testing an Onan regulator. I would think the same technique would work on other models:

There are several videos on trouble shooting and repair of generators. You might want to check these out before spending $300.

Thanks. Mine is not like that at all. I have way more wires and there are no "parts" on it to turn. I know electricity passes through it, it just does not seem to power UP. It will run my microwave, but clearly at much less power. Things take forever to heat up.

This is what mine looks like: https://photos.app.goo.gl/r2qnCRHRGbdDWXor8

[BobC]

Whatever you do, don't spend money replacing expensive parts if you're not sure they need replacing.

I know absolutely nothing about troubleshooting generators but I did find this that might help:

Onan Generator Troubleshooting Article

[tommymsw]

Originally Posted by BobC

Whatever you do, don't spend money replacing expensive parts if you're not sure they need replacing.

I know absolutely nothing about troubleshooting generators but I did find this that might help:

Onan Generator Troubleshooting Article

Thanks, I don;t have much choice though. All I can do is take my best guess. I have found no way to test it. However, this part seems to be what increases the voltage when needed and the generator is not increasing voltage... So, it is either THIS part, or something preventing this part from working.

[BobC]

Although I know nothing first hand, this is giving me the opportunity to learn about these beasts and the trouble they can cause. Here's another link for you that mentions some other potential causes. In this case, it ended up being a carburetor problem.

ONAN Marquis 5000 Low Voltage Problem