Air Conditioning won't turn on with Generator running

**HaroldTerry** · 08-26-2021, 04:38 PM

I recently purchased a 351m. I tried running electrical components (lights, AC, etc.) with the Generator running and I can't seem to get the AC's to run with the Generator running. Also, it would appear the batteries are not charging with the generator running either. Is there some trick to (e.g. switch?) to having electrical power available to the Trailer components from the Generator? I read in the manual that the AC won't run if the fuel tank for the Generator is < 1/4 full, however the tank if full.

**Hoopy Frood** · 08-26-2021, 04:49 PM

On the generator itself, if it's a Onan 5500, is the start switch and two circuit breakers. Make sure your circuit breakers are engaged.

**FirstAscent** · 09-05-2021, 11:54 PM

Originally Posted by HaroldTerry

I recently purchased a 351m. I tried running electrical components (lights, AC, etc.) with the Generator running and I can't seem to get the AC's to run with the Generator running. Also, it would appear the batteries are not charging with the generator running either. Is there some trick to (e.g. switch?) to having electrical power available to the Trailer components from the Generator? I read in the manual that the AC won't run if the fuel tank for the Generator is < 1/4 full, however the tank if full.

Did you ever get this resolved? I don’t have too much to offer but agree to double check your circuit breakers.

With that being said, I have a 381M so very similar to yours, what’s “supposed” to happen is after the generator is running for about 30 seconds the Automatic Transfer Switch will automatically kick it over to be supplied by the genny and then you can run everything. You’ll hear a beep and I usually just wait until the time is displayed on the microwave then I know I have 120v power.

On mine it doesn’t care what the fuel level is, it will continue to run until there is no more fuel.

Btw, you don’t need the genny to turn on lights, they’re all 12v and run straight off the batteries.

**Redapple63** · 09-06-2021, 08:27 AM

You don’t say what type of genny you have, if it is built into your rig or a stand alone plugged into your shore power connection.

First you need to confirm your generator is actually putting out power. Depending on how it is connected could be a problem right there.

Ensure it has sufficient wattage to support your ac unit/s.

The fact that you cannot confirm battery charging etc tells me your are not actually getting power from the genny.