New generator install. No power inside!

**Dsrotter** · 02-11-2024, 04:59 PM

I have a 2023 momentum with an onboard generator I just installed. Runs great but I’m getting no power inside trailer. I wired the generator into the junction box up front which leads to the transfer switch. I checked the breakers on the genny, they are not tripped. Found the automatic transfer switch and I’m getting 117v in and out towards the panel but none of the outlets, AC, microwave or fridge will turn on. No breakers are flipped. I found one GFCI plug in the bathroom and it isn’t tripped. Everything works perfectly when plugged into shore power. I have the solar/inverter package but don’t think this would affect anything. Not sure where to check next? Does the output from the transfer switch go to the main breaker? Was going to pull the breaker and see if it’s coming in. Any help is much appreciated!

**jkwilson** · 02-11-2024, 05:47 PM

I’d check the breaker panel and see if there is power there.

The secret to electrical troubleshooting is to find the last place there is power and the first place there isn’t.

There have been issues with some GD units, though I think older than yours, where the neutral was miswired at the transfer switch.

**Tom Traveler** · 02-11-2024, 10:12 PM

Originally Posted by Dsrotter

I have a 2023 momentum with an onboard generator I just installed. Runs great but I’m getting no power inside trailer. I wired the generator into the junction box up front which leads to the transfer switch. I checked the breakers on the genny, they are not tripped. Found the automatic transfer switch and I’m getting 117v in and out towards the panel but none of the outlets, AC, microwave or fridge will turn on. No breakers are flipped. I found one GFCI plug in the bathroom and it isn’t tripped. Everything works perfectly when plugged into shore power. I have the solar/inverter package but don’t think this would affect anything. Not sure where to check next? Does the output from the transfer switch go to the main breaker? Was going to pull the breaker and see if it’s coming in. Any help is much appreciated!

The generator shouldn't be wired into any "junction" boxes. It should only be wired into a transfer switch with the other input being the shore power cables. Please forgive me if I'm asking obvious questions but I like to start from the basics.

With an inverter and a generator you will have two transfer switches. Do you have two? At least in our Solitude, the inverter transfer switch is in the front battery/power compartment. That transfer switch is fed from either the inverter or from a 120v AC breaker in the main breaker panel. The output of that transfer switch feeds a subpanel, which feeds the refer and the outlet circuits.

The second, much larger transfer switch, is in the basement behind the main 120v AC breaker panel. The inputs to that transfer switch are the shore power leads and the generator. The output of that transfer switch is to the main breaker in the 120v AC breaker panel. In our Solitude, the generator has priority. That means that if the generator is running, the transfer switch routes the generator to the main breaker and disconnects shore power.

If that second transfer switch is wired correctly, and everything works on shore power, and your generator is feeding power into the second transfer switch, the 120v AC devices have to work when the generator is running.

By the way, you don't need to "pull" the breaker to see if it has power. Simply touch one lead of a volt meter to the screw terminal on the breaker and the other lead to the ground/neutral bar in the breaker panel. Be very careful here. A mistake can kill you.

**Dsrotter** · 02-11-2024, 10:43 PM

Thanks for the reply! From what I’ve found there is only 1 transfer switch which is in the basement area. Had to remove a wall panel to get to it. It is labeled inside inputs for generator and shore power, this is what I tested voltage on and got 117v input/output when the generator was running.

Sounds like the transfer switch is located in the front compartment on your model. On my momentum they just put a junction box in that front compartment that the generator connects to. Those are the connections which lead to the generator inputs on the transfer switch.

I’m going to pull it apart again tomorrow but I have looked all over and cannot locate a second transfer switch. Research I’ve done suggests there may be an automatic transfer switch (pass through) built into the inverter but that would mean the wiring would then have to go back into the front compartment.

Because my trailer didn’t come with generator stock (generator prep was installed) but did have the inverter/solar installed, I’m wondering if they forgot the second switch. Might have to go find a dealer with one and see what’s different. Thanks again for your help, hope I can get it resolved and help someone else that runs into the same issue!

**Tom Traveler** · 02-11-2024, 11:17 PM

Originally Posted by Dsrotter

Thanks for the reply! From what I’ve found there is only 1 transfer switch which is in the basement area. Had to remove a wall panel to get to it. It is labeled inside inputs for generator and shore power, this is what I tested voltage on and got 117v input/output when the generator was running.

Sounds like the transfer switch is located in the front compartment on your model. On my momentum they just put a junction box in that front compartment that the generator connects to. Those are the connections which lead to the generator inputs on the transfer switch.

I’m going to pull it apart again tomorrow but I have looked all over and cannot locate a second transfer switch. Research I’ve done suggests there may be an automatic transfer switch (pass through) built into the inverter but that would mean the wiring would then have to go back into the front compartment.

Because my trailer didn’t come with generator stock (generator prep was installed) but did have the inverter/solar installed, I’m wondering if they forgot the second switch. Might have to go find a dealer with one and see what’s different. Thanks again for your help, hope I can get it resolved and help someone else that runs into the same issue!

From what you are saying, I think you do have the correct transfer switch and I might have been wrong about the junction box. Mine came from the factory with the generator which was wired into the transfer switch. With the generator prep, they probably wired the transfer switch into that junction box to make it easy to wire in the generator later. The generator/shore power transfer switch should be in the basement area which is where mine is.

Do your shore power wires go into the other input on that transfer switch and does the transfer switch output go to the main breaker panel? Using a volt meter, test to see if the main 120v breaker is hot when the generator is running and shore power is disconnected.

I also think you do have the second transfer switch I was referring to. It should be right by the inverter.

**JKellerJr** · 02-12-2024, 10:18 AM

Originally Posted by Dsrotter

I have a 2023 momentum with an onboard generator I just installed. Runs great but I’m getting no power inside trailer. I wired the generator into the junction box up front which leads to the transfer switch. I checked the breakers on the genny, they are not tripped. Found the automatic transfer switch and I’m getting 117v in and out towards the panel but none of the outlets, AC, microwave or fridge will turn on. No breakers are flipped. I found one GFCI plug in the bathroom and it isn’t tripped. Everything works perfectly when plugged into shore power. I have the solar/inverter package but don’t think this would affect anything. Not sure where to check next? Does the output from the transfer switch go to the main breaker? Was going to pull the breaker and see if it’s coming in. Any help is much appreciated!

As @jkwilson says, keep tracing it until you find the break in the chain. If it doesn't make the breaker box then something has to be in that link somewhere, though I don't know what.

Originally Posted by Tom Traveler

The generator shouldn't be wired into any "junction" boxes. It should only be wired into a transfer switch with the other input being the shore power cables. Please forgive me if I'm asking obvious questions but I like to start from the basics.

With an inverter and a generator you will have two transfer switches.

I don't think that all units are wired the same. Especially between years and/or if they start using different parts. My '21 375 and my buddies '21 380 both have the junction box in the front compartment. The pigtail that came on my generator might have reached the transfer switch in the front basement if it had gone straight back and back up through the floor. But it would have been tight. I really doubt that GD changes that cord but others could come with a different cord. The pandemic was the wild west. I looked into changing mine and it ain't easy getting into the geney and changing the wires. Mine are only 12 gauge and according to Onan's own manual its supposed to be 10 gauge. I wired the legs on mine together (in that junction box coincidentally) so both legs share the load equally now. Lessening the chance either leg see's a max load.

We only had the 1000w inverter for the residential fridge. It has an internal transfer switch. It just passed AC through when on shore power. I don't know what happens with the larger solar inverter. But it also could have changed over the years.

**Dsrotter** · 02-12-2024, 01:13 PM

Thanks you everyone for your advice. Still unsure about the second transfer switch but I did find a solution. Not sure how they mixed it up but grand design had the “shore power input” and “control panel output” swapped in the transfer switch. Fortunately I never had the plug in when I turned the generator on, it would’ve been sending power to the exterior plug. Hope this helps someone if they have the same issues!

@tom_traveler @jkwilson

**xrated** · 02-12-2024, 01:18 PM

Originally Posted by Dsrotter

Thanks you everyone for your advice. Still unsure about the second transfer switch but I did find a solution. Not sure how they mixed it up but grand design had the “shore power input” and “control panel output” swapped in the transfer switch. Fortunately I never had the plug in when I turned the generator on, it would’ve been sending power to the exterior plug. Hope this helps someone if they have the same issues!

@tom_traveler @jkwilson

That ^^^^ is a huge mistake on their part. That could have gotten ugly!