12 Volt Manual Override Switch

Ok Switches come in both Local (Pictured in earlier replies) and Remotes, also circuit breakers come in assorted designs as well

This is what you need, and how to use it:
12 volt automotive test light from Amazon

Now I linked to one at Amazon.com but you can find 'em at Wall*Mart, Many Hardware stores, Any Auto parts place and Many RV stores. No need to wait for delivery.

You can also use a volt meter but these are easier and faster

Step one, Clip to POSITIVE battery lead, tip to negative,< Bright light... GOOD.. Move tip to frame (any unpainted part) still bright good, Think about where the next test point is (follow POSITIVE wire from battery) and move clip so you can reach, ideally, both the battery and the other end of that wire, Re-check battry, Still bright (Note you are testing the ground (clip) connection) test the other end of the wire, Bright, good, dark bad
Move to the other side of whatever it connected to (Fuse, Breaker, Solenoid or Switch) Same result.. Continue till you find DARK

The problem exists betwen BRIGHT and DARK.

From there we can provide precise help.

ON YOUR MAIN POWER panel.. (in most trailers, Some it may be elsewhere) there is/are one or more fuses we refer to as REVERSE POLARITY.. if your power panel is the intergrated type, with both 120 volt breakers, 12 volt fuses, and the converter all in one assembly.. Not like mine (3 separate assemblies) those fuses are often 30 amp and are often on the right.. If you accidently put the batteries in backwards.. They may be blown.

How to test if batteries are installed backwards

using a digital volt meter ground the BLACK probe.. Touch both (one at a time) battry posts. ONE will give you a reading 12V good -12V bad

Using the test light.. In the tests I cited above if you put the batteries in backwards you will get DARK when you move the clip to the chasssis/frame and test the Positive terminal.. If that happens test the NEGATIVE terminal if that gives you light. you found the problem. Test it.

It probably will NOT be a Battery Switch like this

but more likely a Relay like this

The large terminals are "switched" according to input to the small terminals, from a conveniently located smaller switch. The Relay itself should be near the battery.
Some of those relays have fuses on them.

Don't you at least have a 12v test lite ?

On your battery POS cable that comes out of the 'disconnect switch' and goes to converter is a 30A DC circuit breaker (small box with 2 studs...cable in/cable out on the studs)

It is the main cable 'protection'

Should be an 'auto reset' but can be a manual reset. If manual it will have a small button on side to reset it.
If no reset then it sounds like it has failed (should be 12V DC on both sides...check stud to ground)





Just follow battery POS cable.....should be in forward compartment close to batteries.

IF no CB then there will be a in-line fuse holder with a 30A fuse inside.

(****Could be under a protective cover/box)


And LOOKING at a fuse does NOT mean it is good..test them
Test those 'reverse polarity' fuses on the converter ---the 25A fuses

Do you not have a meter?
NEVER trust visual inspection of a fuse, they can easly have a fracture that is hard to see.
Get yourself an early present

Yeah, guess I'll have to try to use my volt meter, though it makes little sense to me. Never have understood electricity; doesn't help that I'm scared spitless of it! My good RV repairman goes back to work Monday; he may get some business.

You might get more ideas where the "battery disconnect switch" in a 2008 Hitchhiker is in the 5er Forum. Some of those brands have their own forums elsewhere in the web. Is there an Hitchhiker forum? If so they could help with the location.

I know on a friend's Cardinal the switch is in the doorway as a red tab. Our Komfort has a push- pull knob, located in the kitchen, but it is normally pulled out when "closed" so yours is the other way if it says to push it in.

It sounds like that switch you played with near the battery might be it.

Suggest you find an Electrical person with a meter to help you.

One more comment. I looked at all the wires around one of the batteries, coming out of the manual off/on switch. A pink wire had a small 30 amp fuse inline, but the fuse looked OK. Two other wires had what looked like a push and twist connector, about 3-4" long, that might have some kind of fuse inside? One said 7.5 amp and the other said 3 amp ---- sounds too small to be the problem?

I've looked all around the batteries and can see no switch, except for the manual off/on switch near one of the batteries. I have cycled that off and on several times, seems no problem there. I checked 3-25 amp fuses on the converter --- OK. Didn't see any 30/40 amp fuses; are they inside the converter out of sight?

I also removed the plate off the AC circuit breakers, flipped all them off and on, looked at the DC fuses back behind and they are all 15 or 20 amp household circuits, look OK. Don't see any kind of override there.

Yeah, think I hooked up the batteries OK. The new batteries were identical and I was careful to note where the wires attached. Think I got it right.