120v and generator…

[modrob]

I would check gen output at the gen. The issue with many Onan generators is the field compensation circuit. This circuit changes the field voltage to manage voltage sag. Although its been some time, as I recall it has brushes. You might check them for possible replacement next.

Whew! By the time I get this coach in shape, I’ll be a full-fledged tech! LOL Problem is I have other major projects going on and I have to squeeze the RV in when I can…I guess I have to finally admit to myself I got taken pretty good on this coach. I’m about sick with all I’ve found and more to come I’m sure…totally my fault by not doing a thorough inspection and trusting the old couple sellers.
Thanks for your help and guidance.

 

[Kevin D Pem]

Whew! By the time I get this coach in shape, I’ll be a full-fledged tech! LOL Problem is I have other major projects going on and I have to squeeze the RV in when I can…I guess I have to finally admit to myself I got taken pretty good on this coach. I’m about sick with all I’ve found and more to come I’m sure…totally my fault by not doing a thorough inspection and trusting the old couple sellers.
Thanks for your help and guidance.

My mom used to say as people age they become worse images of what they were when young!!! Just because you see white hair doesn't mean they can be trusted!!! Till the day she passed, she had a mellow soul, she must have been a joy to raise!!!

Oh if no brushes the excitation coil in the field would be my diagnosis.

 

[modrob]

UPDATE:
Finally got around to looking deeper. There are only two breakers on this unit, on left side, to the right of the Start/Stop rocker switch. Evidently I couldn’t read the labels clearly and had them OFF instead of ON. Corrected that, and voila! 120 volts now showing up inside. Curiously, I turned on the FAN switches on the overhead AC units, but nothing. Hmmmm…

 

[TheLooks]

Put up a pic of the AC unit and thermostat. By pic I mean the inside cover on the ceiling and any lettering on it.

 

[modrob]

Put up a pic of the AC unit and thermostat. By pic I mean the inside cover on the ceiling and any lettering on it.

I’ll have to get a pic of the thermostats soon…but here are the labels inside both roof units.

 

[TheLooks]

My guess is if you turn on the AC or heat unit and nothing happens it is either in the control box in the AC unit or the thermostat.

 

[modrob]

My guess is if you turn on the AC or heat unit and nothing happens it is either in the control box in the AC unit or the thermostat.

A few weeks back (warm weather) I had both units working fine (cooling) but was on shore power…

 

[TheLooks]

Shore power or 120 vac is necessary for the AC unit to run, but it still is controlled by 12 vdc. The furnace only runs on 12 vdc so unless the battery is dead and the convertor is dead, it will run without 120 vac. The fans on the AC units need 120 vac to run but are TOLD to run by a relay controlled by 12 vdc.(thermostat and control box in ceiling AC unit) Check your voltage with a meter and check the fuses.

 

[modrob]

Shore power or 120 vac is necessary for the AC unit to run, but it still is controlled by 12 vdc. The furnace only runs on 12 vdc so unless the battery is dead and the convertor is dead, it will run without 120 vac. The fans on the AC units need 120 vac to run but are TOLD to run by a relay controlled by 12 vdc.(thermostat and control box in ceiling AC unit) Check your voltage with a meter and check the fuses.

Yes sir, I understand. The furnace part I haven’t started to look into yet—propane is empty anyway…but I’m sure like everything else I’ve been finding, it’ll have issues as well…
All batteries are new and charged…(2 coach and 1 chassis)
I’m just confused for the time being on why AC units/fans would work on shore power, but not with genset running…all breakers/fuses appear to be good so far too.
I’ll keep reading your reply a few more times—I may be missing something…

 

[TheLooks]

Nope, you got it. I would check the transfer switch now. It is supposed to automatically go to generator when the shore power is removed.....or if you have an old system, you have to plug the generator in manually in the electric bay.