No battery power

[NuttyKev]

I have a Heartland Fuel toyhauler and just recently noticed my batteries no longer supply power to it. I park it on the side of my house and leave it plugged in to shore power. I went out to run the generator and unplugged the shore power. Generator started up without issue. Everything working as should be, lights, water pump, and i ran the A/C for a while to exercise it.

Turn everything off, shut down the generator, and i no longer have any lights, or power at all. I go through everything i can think of. check batteries, they are good (they started the generator). Check all the fuses, even replaced them just to be sure. Plug shore power back in, all good, unplug shore power, nothing. I check the little breaker next to the battery thats bolted to the frame, getting power to both poles.

Im at a loss. What else is there to check?

[BB_TX]

If you have +12 vdc on both sides of the auto reset circuit breaker, the only thing between that breaker and the 12 vdc fuse panel should be the battery disconnect switch. Use your meter to verify you have +12 vdc on both sides of your disconnect switch.

[wa8yxm]

There are several breaker designs.. And there may also be a fuse at the ... no that's not it...
Tools needed.. A coil of wire. oh say 14 or 18 Ga is good even 20 but will work
Two Clips (So you can clip onto things) One on each end of the wire.

One "12 volt automotive test light" (Any auto parts store or department)

How to test.

The light has a wire with a clip (Like the ones you put on the wire coil) Start at the battery Clip to Negative tip to positive LIGHT BRIGHT good. Light dark.. Check to make sure the bulb is properly seated.. You might check on a known good battery.. (I often need to re-seat) Light still dark after testing bright on a good battery.. Or dim.. You battery shot. (That was easy)

Assuming good at every point from here on
Move clip to any NOT PAINTED body part.> Still bright.. Good.
Move tip out along the positive wire.. Follow the wire to it's other end and test both sides of whatever is there.. NOTE if you can not find a good ground.. That's what the coil of wire is for (Use it to extend teh test lead on the test light back to a known good ground)

When you find something that is BRIGHT on one end or side and DARK on the other.. Problem found.

[Boon_Docker]

He already checked the 12V breaker.
"I check the little breaker next to the battery thats bolted to the frame, getting power to both poles.

Sounds to me like a loose positive or negative wire at the control (fuse) panel. Happened to me once a couple years ago.

[Gdetrailer]

Reisender wrote:

NuttyKev wrote:
Battery disconnect switch is on. I never use it, but did check it just in case. When you say large 40 amp fuses, do you mean typical automobile type fuses? Because i checked and replaced all of them. If memory serves me correct (Im at work right now and cant look at the RV) there are a handful of 15 amp fuses, one 20 amp and two 40 amp.

Also some trailers have a breaker on the trailer tongue near the battery. It might have a rubberized cover covering it. It’s a physical push to reset type affair. At least on the ones I have seen.

Typical 12V breaker used on RVs is an auto resetting version, looks like this..



Doubt very many RVs have been built with manual reset type which would cause a lot of unneeded warranty service calls..

[BB_TX]

If that TH is a 5er you probably have 2 or more auto reset circuit breakers in the front compartment near the battery(s). They should all have +12 vdc on both posts. They are known to fail.

If a bumper pull then there should be one or maybe two near your battery.

[Reisender]

NuttyKev wrote:
Battery disconnect switch is on. I never use it, but did check it just in case. When you say large 40 amp fuses, do you mean typical automobile type fuses? Because i checked and replaced all of them. If memory serves me correct (Im at work right now and cant look at the RV) there are a handful of 15 amp fuses, one 20 amp and two 40 amp.

Also some trailers have a breaker on the trailer tongue near the battery. It might have a rubberized cover covering it. It’s a physical push to reset type affair. At least on the ones I have seen.

[Reisender]

NuttyKev wrote:
Battery disconnect switch is on. I never use it, but did check it just in case. When you say large 40 amp fuses, do you mean typical automobile type fuses? Because i checked and replaced all of them. If memory serves me correct (Im at work right now and cant look at the RV) there are a handful of 15 amp fuses, one 20 amp and two 40 amp.

Yah. They will be orange but can be one of two physical sizes although they are still 40 amp.

These are technically reverse polarity protection fuses but can blow for a variety of reasons. Check ‘em both. Either one blown will kill the output.

[NuttyKev]

Battery disconnect switch is on. I never use it, but did check it just in case. When you say large 40 amp fuses, do you mean typical automobile type fuses? Because i checked and replaced all of them. If memory serves me correct (Im at work right now and cant look at the RV) there are a handful of 15 amp fuses, one 20 amp and two 40 amp.

[Reisender]

Do you have a battery disconnect switch?

Does your converter have two large 40 amp fuses? If so check then both.

[Ed_Gee]

Auto transfer switch has nothing to do with the 12v battery system; iit only switches 120VAC between shore power input and generator. Quite likely the problem is an inadvertently switched battery disconnect switch.

[opnspaces]

If the generator will start up with the shore power disconnected then as suggested look for a disconnect switch or possibly a stuck auto transfer switch.

[fj12ryder]

No real idea, but could it have something to do with the Automatic Transfer Switch? Have you checked the Battery Disconnect Switch? Perhaps it got turned by accident.