Air conditioning question
 

Getting the overhaul started on my 1978 Hi-Lo. hooked it up to power on a 1100 power inverter that is solar powered. Lights and refrigerator seem to be working. The roof AC doesn't seem to be working. Tried to pinpoint the circuit for it and the closest I found is a 20 amp. breaker. It was on, but I had nothing coming from the AC unit. Anyone here have any experience working on a unit this old?

Haven't worked on a unit this old, so I'd have to ask the question, is it plugged in?
Follow the power from the A/C backward. You'll find the problem.
Tree

I am a total newbie to travel trailers. Had one once parked at a campground for a few years and that is it. I was checking out the electrical system and it looks like there is both a 12V system for interior lights and a power converter for 110v. There is a plug outside above the kitchen window adjacent to the AC unit that says only connect 120v service to it. Is this the power source for the roof AC? Looked at the 1977 manual that is on this site as I do not have one. I am not seeing it there.

photo, Like I've said, never worked on a Hi Lo this old but I have seen older ones that had a coiled or flexible power cable going to the A/C. I'd suspect that's the power source. No idea what the plug ends look like.
I thought someone with an older unit would have piped up by now, but they must all be camping! Hope any of this helps you out. Is there an outlet almost directly below the one you see, on the lower half? Pretty sure the lower feeds power to the upper plug. Just need the cable if so. Might be in a storage bin somewhere.
Tree

AC cord
 

I have a 1990 25ft. HiLo. My AC cord is tucked in an outside compartment on the drivers side. You would pull it out and plug in to the top half exterior outlet. Then you raise the unit up. Go inside and turn the roof top AC on. Hope this helps you.

Sam, you were correct. That supplies the power to my rooftop AC. However, the motor will not turn. I can hear it trying and shut it off. Tried to turn the wheel and it is seized. Now to figure that out next.

AC unit fix
 

Probably better to replace it. Given how hot and humid it was this past summer. You might get lucky and find a used one from a totaled unit or something off craigs list. I had to replace mine a few years ago as parts were no longer available.

Right now I am doing an overall evaluation of what needs to be done to get this camper usable. Not sure what I'll do about the AC. It is a 78 that I picked up for $200. Has had leaks. Most of the ceiling is good except the rear around the vents. The majority of leak damage is to the walls. Tried to get the hot water, furnace and propane refer to work. Have only got the stove to work on propane so far. Refer seems to work on 110v. I have it parked in a pole barn while I work on it.

My A/C would hum and not run. Took the A/C cover off and found that a mud dauber had 'cemented' the outside fan to the housing. Removed the dauber nest and everything worked. Hope this helps.
Beach

Thanks for the info Dee. I will check that out.

Photo, earlier you said you were powering your 110v inverter with a solar panel. You need to have the main power cord for the trailer plugged into a regular 110v outlet from your house or barn. A solar panel will not provide enough amps to run an air conditioner.

Roger

Thanks, I thought of that too. I'll check it out when I get near an electrical outlet with house electric. That said, I have 2 100 watt panels on the roof of my barn and a power inverter to plug the trailer into. It runs everything in the trailer, but the AC on my unit is a separate plug above the kitchen window. I plugged that into my power inverter and it hummed, but the blower would not turn. I took off the inside cover and tried to turn the fan, but it wouldn't budge, so I think it is a problem with the blower.

photobob, unless your inverter is able to provide more than 2000 Watts of power, it will NOT power the air conditioner. You'll probably need a 20 Amp electrical circuit to run it on house power too.

- Jack

The problem with AC is that you need enough amps to get the compressor to turn on. My Honda 2000 has enough to start and run my Coleman Mach 8 9200 BTU unit, but a larger unit would probably need more. Those solar panels won't run it.

Possible you have ruined the AC electric motor. Hum is OK for a few seconds, putting power to a motor that is not spinning can melt the copper coils wound in the motor - I thik, maybe.
It WILL NOT run off an inverter unless it is an inverter rated at over 3,000 watts, or over 20 amps. Then you would need a house of batteries, not just what you have on RV.
Air Cond plug is separated for a reason.
Run all your camper (except H2O heater) off battery.
Save AirC for generator or shoreline power. If you don't have, then you don't have AirC that day.
200 watt solar sounds like a lot but it is not a lot. It is enough for running the camper DC items some. It is enough to recharge and keep charged on sunny days.
It is not enough to run an inverter for any length of time.
Consider using only DC powered things. Save the inverter for when you have to have Alternating Current, and use it sparingly and not for long.
I use my inverter only to charge or run my laptop which only charges on Alt Current. Otherwise inverter is off. Inverter drains power even with no load.
Inverter is inefficient - it changes DC power to AC power and there is loss, then for some things you plug in a power adaptor which changes AC back to DC current.
Don't confuse AC air cond with AC alternating current. lol.
Air cond is usually written A/C,

A/C hum
 

Once again I will state that I had the same indication. I got upon the roof, removed the A/C cowling and found a mud dauber had cemented the squirrel cage to the housing. After I removed the mud dauber's nest everything worked.

Beach

Haven't had a chance to get it home where I can try a 20 amp circuit. The power inverter is 1100 watt and runs off of 2 batteries. I doubt I fried it as it was not plugged in that long and when it didn't run, I unplugged it and tried to turn the blower. I will take the cover off the roof and look in to see if anything is blocking it.

a/c won't start
 

The a/c on my 22t wouldn't start after investigating I found that the fan motor was ceased and the fan wouldn't spin. Had to use pliers to break it loose that only lasted a little while. Eventually I had to replace the fan motor.

The rooftop A/C on my 1969 Funchaser is powered by a separate external cord that is plugged into a receptacle found near the normal 120v receptacle at the outer edge under the trailer. The external cord then runs outside the trailer and is plugged into a receptacle found on the side of the near the trailer top adjacent to the A/C. This external cord is long enough to extend to the proper length when the top is erected and is removed and stored inside the trailer when towing The lower receptacle is covered by a screw on cover; the top receptacle has a flip up cover.