GU without external regulator

[Yoshimura]

The day before we took delivery of our new Roadtrek Simplicity, the dealer determined there was a problem with the GU. Since fixing it could take a few weeks, we decided have to have it fixed locally instead (the dealer is a few hours drive from our place). When the local service center looked at the GU, he immediately said that it was normal that the GU was not charging because there was no Balmar (external regulator). Does the Simplicity usually have a Balmar or does it use the GU basic internal regulator?

[booster]

Originally Posted by Yoshimura

The day before we took delivery of our new Roadtrek Simplicity, the dealer determined there was a problem with the GU. Since fixing it could take a few weeks, we decided have to have it fixed locally instead (the dealer is a few hours drive from our place). When the local service center looked at the GU, he immediately said that it was normal that the GU was not charging because there was no Balmar (external regulator). Does the Simplicity usually have a Balmar or does it use the GU basic internal regulator?

Can't say for the Simplicity, but as long as the alternator used for the GU has an internal regulator, it should charge OK. It will normally give an automotive battery charge profile, however, so wouldn't be a first choice. If they used the normal Nations alternator for the GU systems without a Balmar it would not work as it would have no way to drive the field. It they hooked up straight 12v to the field, you would get way over voltage, which I think you have had.



For a single 105ah battery, there is really no need for the GU for charging it, as the standard alternator with separator should be able to handle it easily. Even running the microwave off a larger inverter should be good off the engine alternator. The only thing that might be a need for the GU would be if you want to run the coach AC off the running van engine, assuming a big enough inverter, but at that point you could just use the dash air.

[Yoshimura]

An external regulator would connect there (red arrow in picture) but considering the very close proximity of the panel, I don't see how this could have been designed for an external regulator.

[Yoshimura]

Originally Posted by booster

Can't say for the Simplicity, but as long as the alternator used for the GU has an internal regulator, it should charge OK. It will normally give an automotive battery charge profile, however, so wouldn't be a first choice. If they used the normal Nations alternator for the GU systems without a Balmar it would not work as it would have no way to drive the field. It they hooked up straight 12v to the field, you would get way over voltage, which I think you have had.



For a single 105ah battery, there is really no need for the GU for charging it, as the standard alternator with separator should be able to handle it easily. Even running the microwave off a larger inverter should be good off the engine alternator. The only thing that might be a need for the GU would be if you want to run the coach AC off the running van engine, assuming a big enough inverter, but at that point you could just use the dash air.

Yes, it's the Nations alternator. I checked on their site and it seems that the Balmar is only required to gain more optimal performance or when using Lithium batteries.

[booster]

Originally Posted by Yoshimura

An external regulator would connect there (red arrow in picture) but considering the very close proximity of the panel, I don't see how this could have been designed for an external regulator.

That is tight, including the output post which could short out to the panel, especially since the engine moves around.


Regardless of GU or not, there would be wiring to that connector to get power to the alternator to initiate it and make it run, and all of it looks to not be there unless there is another wiring entry we can't see.


It is almost as if that is not the correct alternator do to it's orientation. A lot of the Nations alternators appear to be "clocked" to point the terminals in different directions.


There certainly does seem to be something really wrong with either the parts, install, or both for you GU. Has Roadtrek seen that pic?

[booster]

Originally Posted by Yoshimura

Yes, it's the Nations alternator. I checked on their site and it seems that the Balmar is only required to gain more optimal performance or when using Lithium batteries.

That is new to me, first I have heard that as they have been putting them in Roadtreks with AGM for a long time, I think.


If that is the case, it would have an internal regulator, which in most of the Nations stuff from DC Power would have Denso internal regulator which is a very good regulator. The question would be if the alternator regulator wiring has been setup to be internally self exciting by jumpering to the main battery connection. If it is, you would likely have to remove the alternator to find out for sure. I don't particularly like that kind of setup because it keeps the alternator active and using a bit of power all the time even with the engine off so having the turn on control from the engine running 12v power is more desirable.

[booster]

I just went to the Nations site and found the referenced comments about needing a Balmar. This is in the what you need section.

An alternator excitation harness to turn on the secondary alternator, and this kit will not cause any check engine codes/charging lights

• You can add a MC614 Balmar External Regulator to your package to gain more optimal performance. Note: If you are using Lithium Batteries, this is a requirement

This would indicate that it should have a harness connected to that connector that ties to the engine power, but as was mentioned, there is no room. The same connector might also be used for the connections from a Balmar regulator or might be pigtailed.



The statement about lithium seems to say you have to have it for lithium, but also says you get better performance with other battery types, too.


One thing I know from personal testing on a DC Power alternator with internal regulator is that the internal regulator lets the alternator run much hotter than the Balmar. If it is a Denso internally, it will have a pretty decent charge profile, however, for AGM or wet cells, and will turn itself down in voltage it it thinks the batteries are full. There are two different Denso regulators available with different base voltages, IIRC they run at about 14.2V or 14.6v when I tested them.


I am still at wondering if it is the wrong alternator.

[booster]

Looking at the pic of the alternator and the panel it is hitting compared to the FitRV pix, it appear that the panel is toward the front of the van compared to the alternator? That, combined with the fact that the panel looks to be held on with pop rivets might indicate it is a Roadtrek shield to protect a low hanging alternator. If that is the case, it may have taken a hit in shipping and gotten pushed back against the alternator so no room for connectors or broke it off, etc. Dodge wouldn't be putting stuff on with pop rivets, I think, so it is likely a Roadtrek piece and should be easy to remove to see if things are bent or not. The alternator does look very close the one in the FitRV pix I could find.

[avanti]

What does "GU" stand for?

[booster]

I assumed "generator unit".

[avanti]

Originally Posted by booster

I assumed "generator unit".

I this RoadTrek talk?

[booster]

I guessed wrong, it is Roadtrek speak and is "generator, underhood".

[GeorgeRa]

So, your GU could be very different than my GU, both Generators but one Under the hood and the other one Under the floor. Does it really take so much effort to type a few more letters for the sake of a message quality?

[cruising7388]

Originally Posted by avanti

What does "GU" stand for?

It's a Roadtrek acronym for the second alternator.

[ManWonder]

Originally Posted by avanti

What does "GU" stand for?

I was wondering if the OP meant UG as in underhood generator.

[markopolo]

This recall - https://www.nhtsa.gov/recalls?nhtsaId=18V712 might apply to Yoshimura's RV.

Some detail here: https://static.nhtsa.gov/odi/rcl/201...8V712-6084.PDF

[booster]

If the opening shown really is the location where the internal regulator would mount, I wonder how they will get the wiring out. If it was external like the Balmar it would be just two wires so they could bend them around the obstruction. Will be interesting to see a pic after it is done.