Generator/Shore Power Work, Battery Power Doesn't

whemme wrote:

BrocNeal wrote:
Now when I use the generator or shorepower no AC or appliances. But if i plug into shore power i have everything but lights, but the appliances and AC work. Would that indicate the converter is bad?

You are confusing above. First you say when I use the generator or shorepower there is no A/C or appliances working. Then in your next sentence you say if you plug into shore power then you have everything’s except lights. Please explain???

Sorry when I edited it I must've forgot to delete that part. So with shore power and generator power I have A/C and appliances working but no lights. Then when they're not on the lights work fine off of the battery. Does that make more sense? I totally missed that!

I wonder if you have an RV power transfer switch that is not working properly. But being a 1979 model year, you might not have one unless someone added one later. It is a gray electrical box located inside the house close to the generator. It measures roughly 6"x6" x 3" deep.

Google "RV Power Transfer Switch" for pictures on what to look for.

BrocNeal wrote:
Now when I use the generator or shorepower no AC or appliances. But if i plug into shore power i have everything but lights, but the appliances and AC work. Would that indicate the converter is bad?

You are confusing above. First you say when I use the generator or shorepower there is no A/C or appliances working. Then in your next sentence you say if you plug into shore power then you have everything’s except lights. Please explain???

So I replaced the circuit breakers and now I have power to the lights with the battery. Now when I use the generator or shorepower no AC or appliances. But if i plug into shore power i have everything but lights, but the appliances and AC work. Would that indicate the converter is bad? I didn't see any fuses on the back side of the fuse panel, there is a circuit breaker on the back, but it seems to be working fine. It's got matching voltage to the battery on both posts.

Fuse on converter blows when you reverse polarity.Converter is behind the fuse panel.There are 2 fuses check both that's where i would look unless i misunderstood the post.

Yes sounds like the plan I would follow. But first look at the breaker with the 0 volts post. Check carefully for a small reset button. Most do not have a button, but some do so it's worth looking.

Next you could try disconnecting the wire from the 0 volt post. Give the breaker a minute to cool off and see if you now have 12.4 volts on both posts.

If yes then there is a short further downstream tripping the breaker.
If no then you have a bad breaker.

Another option that might yield some results is to plug in shore power or start the generator. Make sure to reconnect the 0 volt post if you disconnected it previously. If the 0 volt post now has power it tells you the converter/charger and fuses are all good back up to the suspect breaker. But you should be reading something like 13.6 volts on one post and 12.4 on the other post because the breaker is bad and isolating the two posts.

So I went and got the voltage and it's right at 12.4. Then i tested the 2 circuit breakers/Fuses in the battery box and I'm getting 12.4 on 3/4 posts. So I guess I will start there tomorrow and see if replacing that will change anything. I have a feeling it's a little bit bigger issue than that but maybe I'll get lucky. If that doesnt work, I assume the next step is to follow that line that isn't showing 12.4 and see where it goes, which I'm thinking is the breaker box inside the living quarters and see if theres a fuse popped on that line?

12.4 is not dead, but it's about 60 percent discharged. The information that sticks out though is you get 12.4 at the battery when the generator is running. That sounds like you still have a battery shutoff switch or a blown fuse. You are probably going to have to start tracing wires from the house battery to the inside. As bobndot suggested focus on the grounds first.

Leave the generator off and the shore power unplugged. Use your meter and measure the voltage between the positive and negative terminals of the battery. This is your battery voltage, write it down somewhere. Every voltage check you take below should show very close to battery voltage.

Remove both ends of the ground wire, clean off any rust and reconnect. Check voltage from the battery positive to the frame mounted end of the ground.

From there start following the positive wire. Look for any old circuit breakers or fuses. Once you find one use your meter to check the battery voltage on both sides. On a circuit breaker you can connect from each post one at a time to ground. You should get the same battery voltage on each post.

If you find a fuse you can poke the positive lead of your meter to the slots on the back of the fuse. You should get the same battery voltage on both sides of the fuse. If you get voltage on one side but not the other, the fuse is blown.

Edit: Wait, an RV that old probably has glass fuses. If glass, then measure the voltage from each metal end of the fuse to a good ground.

If you can't find a bad fuse or breaker then start looking for the fuse\breaker box. Not sure on a rig that old, but I imagine it's a small panel with a door (probably metal) mounted on the wall somewhere in the living quarters. Find that door and firmly turn every breaker and then back on.

Now see if you can find a good enough ground to check both ends of the fuses. I'm assuming they are glass fuses so just measure from each metal end to ground. You should get the same battery voltage reading on all fuses.

If you do not get battery voltage, or you see some abnormally low number then you have a switch or blown fuse between the battery and the fuse panel.

If you find close to battery voltage at the fuse panel then start the generator and measure the voltage at the fuses again. With the generator running you should be seeing a number higher than battery voltage.

If you have higher voltage, then start tracing back toward the battery until you find generator voltage on one side of a fuse or circuit breaker and battery voltage on the other side. Fix or replace any component that shows a difference between the two ends.

Good luck and come back and let us know what you find, and we'll have more suggestions.

Maybe the ground from the negative battery post is not making ground to where its grounded on the chassis. Corrosion .