Basement AC not blowing cold air. - Page 2

tommymsw · 07-24-2018, 04:35 PM

Quote:

Originally Posted by 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

Yea, I read this one. That is where I got the idea about the regulator. I highly doubt it is the carburetor. It was just cleaned a month ago and I have been running the generator once a week for the last few months. It seems to run fine, it was just that my AC stopped working one day. Then I noticed the gennie was not throttling up as normal. Whatever mechanism controls the throttle seems to be the problem.

I can manually rev it up just fine! Engine runs and sounds good.

BobC · 07-24-2018, 05:52 PM

It sounds like you're ahead of me, good luck. I'll be curious to see how it works out.

Jim_HiTek · 07-24-2018, 07:07 PM

This is where I go to get Onan generator troubleshooting instructions, they also carry generic parts: https://www.flightsystems.com/troubleshooting/

I should mention that their troubleshooting guide is excellent.

tommymsw · 07-24-2018, 11:33 PM

Quote:

Originally Posted by Jim_HiTek

This is where I go to get Onan generator troubleshooting instructions, they also carry generic parts: https://www.flightsystems.com/troubleshooting/

I should mention that their troubleshooting guide is excellent.

Yea, I have seen this also. And even though the hyperlink says "voltage regulator and control boards" there is little to no info on each. And MY problem is not mentioned in the troubleshooting section. I also think they are referencing newer models than mine only.

some of the things say it "could" be the carburetor, but I just find that hard to believe. I can manually increase and decrease the RPM, so the fact that it does not do it automatically, seems to me, it is electronic? I think if it were mechanical, I would not be able to manually do it.

BobC · 07-24-2018, 11:44 PM

At the very least I'd see if I could find a shop to test your capacitor/regulator.

BlueMoose105 · 07-25-2018, 05:51 PM

Tommy,

Like the other people who have posted replies here, I want to help you. But I don’t see a signature with your motorhome’s year and model, or your generator’s make and model. I don’t see any specific information in any of your posts. So what do you have specifically?

I had a start capacitor blow out on my 2010 Adventurer with basement air in February 2017 while wintering in Texas. The capacitor also burned up some wiring that required me to remove the whole A/C unit from the basement so I could get at the hidden wires. Bill Elsenpeter's excellent documentation (referenced in post #7 by BobC) on basement A/C repair was a lifesaver for me.

Please post your specific models and I'll try to help.

sh1seadad · 07-25-2018, 06:23 PM

The generator will run you ac with no problem. Have you checked your air filter and cooling Coil it may need to be cleaned

tommymsw · 07-25-2018, 07:46 PM

I have a 2000 Adventurer. The generator is an Onan 5000.

i am sure it is NOT the AC, or at least I am sure the generator is NOT working right. It is not JUST the AC. The microwave also runs with lower watts than it should (things heat up slowly). So does a space heater. I can get the fans to run on LOW, but when I turn them to HIGH, they keep running at LOW.

I know thew problem is that the generator is NOT cycling up to deliver more power when it needs it. (And won't run the compressors in the AC). I am just not 100% sure WHY it will not cycle up. My best guess is the voltage regulator.

the generator USED to cycle up when the compressors came or, or I ran the microwave. Not it just stays running at normal speed.

peggwn · 07-26-2018, 07:27 AM

We have a similar, if not the same issue. Our AC seems to run fine on the shore. When on the genset the AC seems to draw less amps (Onan Emerald 5000 for 30Amp service). We had the genset tuned and I have replaced all the start and run capacitors.

#1 starts great and settles at 11-12 amps. When #2 kicks in, there is the usual spike to about 28-30 amps, but then the draw settles down to 13-14 amps. That doesn't make sense to me. I am interested in what your situation turns out to be and how it is resolved. Thanks

jdkskyking · 07-26-2018, 07:35 AM

In the for what it’s worth column, on my 08 Journey I noticed the basement AC unit wasn’t dripping much from the condensation drain.
I ran a nylon brush up through the rubber drain and cleaned it out.
It drained a steady stream for 20 minutes.
The unit was much quieter after that.
There’s no telling what damage had started, had been done, or what my future trips will bring because of it.
Good luck.

BobC · 07-26-2018, 08:25 AM

Good idea, jdkskyking, mine isn't dripping much either which I chalked up to our low humidity. I'll clean it and see what happens.

Hopefully the capacitors I ordered will arrive today, i hope they fix my compressor #2 issue.

jdkskyking · 07-26-2018, 08:30 AM

For me, it all started when I went to the bedroom and first thought I had left the engine running. Not the case. AC unit vibrating and loud!
When I have time.... I’d like to remove the unit and inspect it.

jdkskyking · 07-26-2018, 08:32 AM

Was there power to the #2 capacitor?

BobC · 07-26-2018, 08:47 AM

The #2 run capacitor is rusty and there are signs of leakage under it. Since they're relatively inexpensive, I decided to replace it and, if that doesn't fix it, I'll take the time to troubleshoot things. I can hear #2 try to start but it doesn't run. To be safe, I also ordered a start capacitor.

BlueMoose105 · 07-26-2018, 08:53 AM

Tommy,

Onan 5000 is not specific enough to really help you. The 2000 Adventurer brochure lists the standard generator as an Emerald 5000, with an optional Emerald 6500. But the parts list for an Adventurer 35U (may or may not be what you have, just what I found when searching Google) shows two different Onan Emerald 5000 models depending on the build date. Can you get the model number and serial number of your generator from the nameplate? Photos would be best.

My generator has two circuit breakers on the front of it. Yours may have them on the side of the generator's control panel. Try resetting them by turning them off and back on.

Also check that none of the circuit breakers in your 120V breaker panel have tripped. My panel has two for the A/C System, A/C Circuit 1 and A/C Circuit 2. Both of those must be on for the A/C to work properly. My panel is located behind a door on the steps side of the kitchen sink base cupboard.

Why do you suspect the voltage generator is bad? On my generator the governor works in conjunction with the voltage regulator to increase the throttle when the load lowers the engine's RPM and output voltage.

Hope this helps.

mikf · 07-26-2018, 09:54 AM

Quote:

Originally Posted by BlueMoose105

Tommy,

Onan 5000 is not specific enough to really help you. The 2000 Adventurer brochure lists the standard generator as an Emerald 5000, with an optional Emerald 6500. But the parts list for an Adventurer 35U (may or may not be what you have, just what I found when searching Google) shows two different Onan Emerald 5000 models depending on the build date. Can you get the model number and serial number of your generator from the nameplate? Photos would be best.

My generator has two circuit breakers on the front of it. Yours may have them on the side of the generator's control panel. Try resetting them by turning them off and back on.

Also check that none of the circuit breakers in your 120V breaker panel have tripped. My panel has two for the A/C System, A/C Circuit 1 and A/C Circuit 2. Both of those must be on for the A/C to work properly. My panel is located behind a door on the steps side of the kitchen sink base cupboard.

Why do you suspect the voltage generator is bad? On my generator the governor works in conjunction with the voltage regulator to increase the throttle when the load lowers the engine's RPM and output voltage.

Hope this helps.

I agree with everything he said. If you left your hot water heater on electric you may have tripped one of the breakers at the gen set.

tommymsw · 07-26-2018, 10:55 AM

Quote:

Originally Posted by BlueMoose105

Tommy,

Onan 5000 is not specific enough to really help you. The 2000 Adventurer brochure lists the standard generator as an Emerald 5000, with an optional Emerald 6500. But the parts list for an Adventurer 35U (may or may not be what you have, just what I found when searching Google) shows two different Onan Emerald 5000 models depending on the build date. Can you get the model number and serial number of your generator from the nameplate? Photos would be best.

My generator has two circuit breakers on the front of it. Yours may have them on the side of the generator's control panel. Try resetting them by turning them off and back on.

Also check that none of the circuit breakers in your 120V breaker panel have tripped. My panel has two for the A/C System, A/C Circuit 1 and A/C Circuit 2. Both of those must be on for the A/C to work properly. My panel is located behind a door on the steps side of the kitchen sink base cupboard.

Why do you suspect the voltage generator is bad? On my generator the governor works in conjunction with the voltage regulator to increase the throttle when the load lowers the engine's RPM and output voltage.

Hope this helps.

I have an Onan Emerald 5000 generator model 5BGEFA26100P.

It is not the circuit breakers, I have checked them all. Plus as I have mentioned, the AC does run. Plus it is NOT just the AC, it is EVERYTHING electric in the RV. I do have two switches on the side on the generator, I have switched them on and off. You are told to do so when you start and stop the unit. One switch turns on the "generator" part of the unit, I have no idea what the 2nd switch does... the manual shows the second switch, but ignores it in the documentation.

"Why do you suspect the voltage generator is bad? On my generator the governor works in conjunction with the voltage regulator to increase the throttle when the load lowers the engine's RPM and output voltage." ----

I suspect it is bad because mine does NOT do that. It USED to do that, but it does not now. When I add load, the generator does NOT throttle up, nor does the voltage increase. The engine continues to run at idle and only throws minimal power. I can crank the rpm up manually, but it no longer does it on it's own when given load.

Engine appears to be running fine, the only issue is that it no longer auto throttles up. From what I can tell, this is the job of the regulator.

https://photos.app.goo.gl/XEbW9kVUchY9umTH6
https://photos.app.goo.gl/T2MvEre83mm1DcBM7

dickb46 · 07-26-2018, 04:06 PM

I just turned on my A/C on 20 amp house power. 2003 Journey. The a/c came one and the refer went to gas. It dropped the inside air temp from 86 to 70 in 30 minutes

BlueMoose105 · 07-27-2018, 09:28 AM

Tommy,

I now understand why you are focusing on the voltage regulator. The governor on your model is a mechanical one, so if the electrical load was bogging down the generator, the governor would be increasing the throttle to maintain the engine speed and thereby the the frequency and voltage.

This service manual https://rich.homeunix.com/gravely/en...t/965-0528.pdf has some good information on the generator in Section 8 which begins on page 103 of the PDF document. Especially look at the Troubleshooting table on page 110 (manual page 8-8).

Another thing that stood out to me was about the brushes and slip rings. I didn't notice anything about how many hours the generator has run, but the condition of the brushes and slip rings would be good thing to look if your generator has several thousand hours on it, even if you wind up having to replace the voltage regulator (VR).

There is a testing procedure for the VR on manual page 8-15, PDF page 117. You need to use a multimeter with diode testing capability. Most digital multimeters have that capability. If you don't have one, maybe an auto parts store has one you can use. Take the VR there if you need to.

Also, I would check the voltage in the coach with the generator running, but no real load on it, so leave the AC off and the microwave plugged in but not running. Check the voltage at any receptacle. My generator puts out about 118 volts, and fluctuates less than 0.3 volts. Yours should be about the same. Then start the microwave and check the voltage again. Does it stay steady at the previous voltage, does it drop and stay steady, or does it drop and fluctuate?

If the voltage drops and stays steady, I think you may have a governor issue. Maybe it's stuck or disconnected somewhere.

If the voltage drops and fluctuates, I think you are looking at an intermittent issue such as the brushes and slip rings or a loose or corroded connection. Have you checked that all of the terminals, lug nuts, breakers, etc. are snug? At the generator, the transfer switch, and the electrical panel in the coach. They have been known to loosen over time with all of the vibration from traveling. Also check the VR connection. Disconnect the VR and look at the contacts for corrosion. I would clean the corrosion with an Electrical Contact Cleaner spray, and use a dielectric grease on the contacts before reassembling the connector.

Let us know what you find. Here's hoping it's something less expensive than the VR.

BobC · 07-27-2018, 09:51 AM

Good post, BlueMoose105. This is very helpful, not only to the OP but to all who might be looking for help in the future. I'm just getting ready to service my 2002 Suncruiser 35U's generator that I haven't used other then to test run it (but not under a big load). If I encounter similar problems, I'll check things out as you suggest.