General Boards > General Discussion

Low voltage fuse box melt down

(1/6) > >>

Jim Shunkwiler:
Looking for any thoughts as to why my low voltage fuse box would melt down and  catch fire. We had just disconnected shore power and using generator power. I just finished  hooking up the  toad. I entered the coach and smoke detector was going off. I saw  the smoke and found the source when I opened the bathroom door. The  coach filled with smoke but I was able stop the burning by turning off low voltage in battery compartment and shutting down the generator. I have since taken the two power wires off the damaged fuse box and taped them together. I'm able to use generator so I have AC but no lights. It appears to be the wire harness  labeled HOD Data that started the problem. I also need help finding  a replacement board. I'm hoping the circuit board just failed and i don't have another problem. How  do i know? Thanks  for any  feed back you can supply.

Gerald Farris:
Jim,
What year and model coach do you have?

Gerald

Jim Shunkwiler:
2006 Beaver Monterey

Gerald Farris:
Jim,
I personally have very little experience with the multiplex wiring on your model coach, but normally a failure like the one you experienced is caused by a poor connection that causes high resistance when you are under a high amperage draw. You may contact Ken Carpenter at BCS (Beaver Coach Sales) for more insight into the problem.

As for the parts to make the repairs,  BCS or Northwest RV Supply in Eugene Oregon will probably have the parts.  

Gerald

Edward Buker:
Jim,

Is this just a fuse board or are there electrical components on it also? Were electrical components on the board the source of any heat? Is it possible to take a photo or two and post them, at least one of them being a close up of where the burning started. Usually that is what appears to be the darkest spot. A close examination to see if something on the board moved, shorted, and caused the issue. Sometimes you can get sufficient heating with current flow when a connection point is loose. This seems like a more severe situation of over current than that. If components like resistors and ICs are on the board they can internally short out and become a heat source.

The other thing to look at is the HOD wire (I do not know its function), does it connect through a fuse on the board or is it a sense or supply wire with no fuse at its connection point. That wire could be shorted elsewhere and if there is no fusing at the board for this wire it could be the problem, pulling an overcurrent condition from the board. If it is fused, was the fuse the right size?

Assuming the problem is the HOD wire. If you get a new board and start on repairs, the function and normal current draw of the HOD wire needs to be understood. Maybe Monaco or BCS can help provide some info for this wire and if they have seen this problem before. If it is a design issue you are probably not the first.

In the repair I would add a fuse holder and appropriate fuse to that wire. If the new HOD fuse did not blow I would put a DC amp meter in series with it or a clamp on DC amp meter and get some measurements. If this wire was the source of the issue and not something on the board then tell whoever does the repair that you want this HOD line fused properly and the current measured as part of the repair.

As far as running on the genset that should not have had an influence given that supplies AC. It does power up the DC charging system but you had no indications that was an issue. As far as just hitching up the toad, that uses DC but source is usually comes out of the chassis side of the DC wiring and this seems like a house DC fuse box issue.  Hope this helps in some way....

Later Ed

Navigation

[0] Message Index

[#] Next page