Forum Discussion

bplotnick1234's avatar
Dec 02, 2013

Electrical issue

I posted an earlier problem that I was having with my motorhome under "Inverster problems". I don't believe that it is the inverter and I hope to get a couple of new answers with a fresh post. The synopsis of my problem was that I had no power to my coach when just running off of batteries. I have done some trouble shooting over the past few days and may have singled it out. Thanks to everyone that helped me on the other post, it helped out greatly in isolating the problem.

Okay, I got the motorhome at the house and found the box that houses the relay/isolators. With the coach and chassis switches both on both solenoids are getting power. I have been able to track down the coach solenoid by turning off the cut off switches one at a time. I noticed that both solenoids or relays have a 5 amp fuse on each side. I checked both of them and they are fine. I noticed that above the relays for the coach there is a thin box or small panel that has 6 bolts coming out of it with 3 on top and 3 on the bottom. 5 of the 6 bolts are hot. There is one on the bottom right side that has two large gauge red wires coming from it that appear to disappear under the motorhome into no mans land. This bolt shows cold when tested and has no power to it.

I used a wire and quickly jumped this bolt with one of the hot wires and it now works several appliances and lights in the motorhome. Does this mean that the block or I guess they are called buse panels or wiring panels has one bad bolt out of the 6. If so, can I just jump that bolt or move the wires to an empty bolt (2 are empty)? I just don't want to jump or move that wire and later have a major mess on my hands with melted wiring elsewhere in the motorhome. Has anyone heard of these small wiring panels going bad at just one bolt?
  • It has gotten dark today so I will try and get those items photographed tomorrow. There is a fuse on both sides of both relays and none of them are bad if that says anything. There is sooo much wiring in this box. It makes it hard to narrow down a single thing. I am also going to try and contact Coachman tomorrow on this small panel and see if they can tell me anything.
  • Auto mparts stores like O'Reillys or auto zone.
    Locate the battery disconnect for coach, follow the wires on the output side. One of them shoiuld go to a circuit breaker before entering the rig.
    Can you see a make and model of the battery control center?
    Maybe post a photo?
  • Thats a good idea. Anyone know the best place to buy a breaker for this application?
  • Hi,

    I'd go for an automatic circuit breaker instead of the fuse.

    Size it to protect the wire. i.e. if it is #10 then 30 amps #8 40, #6 50 etc.
  • I did look for them, but I did not see any. Once the wires leave the battery box they are in a protective sleeve and trying to follow all of that wiring is next to impossible. I did jump the wires (two large red wires) to a empty post that showed positive. Everything worked great in the motorhome like it used to. The water pump worked, lights, water heater, etc.. I had full power to the fuse box. I am wondering if the one post on the board has gone bad. I checked the board for the chassis side which looks almost identicle and they are all positive. Anyone ever heard of one post going bad? Are these circuit type boards on the back? I may just wire in a jump wire with an inline fuse and see how that works. I would like to move these two wires to a positive terminal on the same board, but I am reluctant to do so without input from someone who already has done that. If I use a jumper wire with an inline fuse does anyone have input on what size of fuse to use? I did notice that when I turned my battery coach switch to store it cut the power to everything, even my jumped cables.
  • Have you looked for a small DC circuit breaker? It should be between the battery disconnect relays and the DC power distribution panel.
    They should be about and inch cube with two #10 studs to connect the wires.
  • Whoops, and yes I have checked every in line fuse i can find and they all appear to be okay.