Electrical problem 345

pjude · 07-09-2007, 04:15 PM

Hi! Last evening I noticed that as it was getting dark the 12V lights began to dim even when the genset was running. The AC units are working fine. When I started the engine the lights brightened up to their usual glow. Today the coach battery is DEAD and had to be jumped to start the coach. Any ideas on where to start looking for the problem. Just a guess but could the inverter have gone bad?
Thank you,
Pete

guy99 · 07-09-2007, 04:42 PM

First thing I would check is the circuit breaker for the 120V outlet that the converter plugs into. On my 84 310 it is the GFI breaker in the 120V box.

I'm confused about the batteries. On my rig there are three batteries, two coach(house) batteries and one chassis battery. All of them are charged by the alternator but only the coach batteries are charged by the converter when the genset is running or when plugged into shore power.

The chassis battery is the only one used to start the engine (unless I use the battery boost). My chassis battery can not be discharged by house lights, furnace, water pump, etc. because it is isolated from the coach (house) load.

Pop Rivet · 07-09-2007, 05:08 PM

Sounds like high resistance connectors to me. To check the inverter, locate the DC output leads. Disconnect the A/C power and take a reading of the DC voltage. Restore the A/C power and take another reading of the DC voltage. Normal A/C off, DC should read in the 12 volt range. A/C on, DC should read 13.5 volt range.
If you get low DC voltage readings with the A/C on and off, Disconnect the batteries and take the DC readings with the A/C on. If the DC voltage increases, I would have the batteries tested.

pjude · 07-09-2007, 07:24 PM

Since my 12V lights brighten when I start the engine I think there is a problem with a short...The fact that the air units are running off the genset but the 12V lights are not ='s a problem somewhere.
Pete

guy99 · 07-10-2007, 12:45 AM

The air units have there own 120V circuits. In order for the genset to make 12V power it energizes a 120V circuit which powers the converter which makes 12V power. This is why I suggest you check the 120V breaker which supplies power to the converter.

The alternator makes 12V power directly and does not require the converter.

pjude · 07-10-2007, 05:47 PM

HI! Thanks to all that responded ...problem was with the breaker. It would be nice if the manuals were correct on certain items...Mine lists the breaker box as being under the range on a 345 when it in fact is above the rear window.
Took me a while to locate it.
Thanks again to all! I know I'll have more questions as this remodel progresses. Pete