Generator issue

[trode]

This past trip in my 2004 Seabreeze was in unusually hot weather, and had passengers too. Normally I just run dash air and it is adequate for me and copilot, but due to passenger and high temps I decided to run generator with roof air this trip. Now I have an issue I guess I need to diagnose, hopefully with the help of people here since I know just enough about electrical system to get by. If I run the generator while driving and DO NOT run some substantial load on chassis battery, the battery light on the dash comes on.

Here is my example, generator running I start the engine, after a moment or two battery light comes on, I put on running lights and for a few seconds it goes off but then back on. If I shut off lights and turn on dash air with fan running light will stay off, and does so for entire trip. The dash fan is running is "required" load to keep light from coming back on. My assumption is that I may have an overcharge situation with the generator running and the engine running, since I am then getting charge to chassis battery from charger and alternator.

Am I assuming correctly? More importantly how is this situation rectified? Please keep any recommendation in simple language, I know just the basics on electrical as already mentioned. And location of suspect parts would be helpful too. Thanks

[twinboat]

You are the second in 3 days to have this condition.

You are not overcharging, just fooling the alternator light into thinking the alt is not charging.

The house charging system is connecting the BIRD and taking over the charging of the chassis batteries.
The control for the battery light sees voltage higher then the alternator output and decides it is not charging.

[trode]

Originally Posted by twinboat

You are the second in 3 days to have this condition.

You are not overcharging, just fooling the alternator light into thinking the alt is not charging.

The house charging system is connecting the BIRD and taking over the charging of the chassis batteries.
The control for the battery light sees voltage higher then the alternator output and decides it is not charging.

Is this condition harmful? Will I do harm to alternator by running like that? Anyway to correct?

Thanks

[twinboat]

In my opinion, no harm will come.
Having said that, I can't wait for the opposing comments.

[trode]

Originally Posted by twinboat

In my opinion, no harm will come.
Having said that, I can't wait for the opposing comments.

None seen, I am going with your advice.

Just curious what the BIRD is?

[twinboat]

A BIRD is a Bi-directional Isolation Relay with Delay.

It is a component that senses charging voltage from your house batteries OR your chassis batteries and combines the 2 battery banks into 1.

If driving, the engine alternator will connect to the house batteries and charge them, as long as the starting batteries needs are met.

While on shore or generator power, the house battery charging system ( converter or inverter/charger ) will do the same, only in the other direction.