Almost burnt down my Metzendorf..

[greg755]

OK now I am really puzzled..


I'm driving down the road and my breaks lock up, so I jerk around with the controller and they free up. About two minutes later they lock up
again....

So I get out to take a look and smell something burning, I open the door of the Metz and to my Horror it is filled with smoke.

So I get to the battery compartment and see flames, she is on fire....

]I quickly yank the wire off the battery blow out the wire that is on fire and run out side and disconnect the the trailer from the car...

This is not good... Big trip to the ADK tomorrow and ole #25 is in peril.

After the smoke clears, I get to work. The #4 wire (7 round connection) that charges the battery is fried, one ground wire is fried and 1 wire to the breaks is fried...

So I cut the # 4 wire from the battery connection and from the pig tail up front. It is melted from the battery to the front end of the pig tail. I check the wire coming from the car it is OK

So I'm wondering why the in line fuse at the car battery didn't blow as this is a # 8 wire and you would think a 30 amp fuse would blow before melting it.

So I re-run the ground wire and the light wire and all lights work again.

None of the wires going to any of the 12 volt receptacles got damaged.

So my question is what caused the charging wire to melt? Why didn't the in-line fuse in the car stop it from burning? Why didn't the wires from the car battery to the jack (at the back of the car) get fried? (same size wire as the wire in the trailer pigtail)

The two batteries are hooked up positive to positive and negative to negative, with a negative wire going to the trailer for a ground.

It damaged none of the 12 volt system (fuse block , fuses, circuit break) it only melted that one wire, the lights all work and the elec breaks work...

Can any one set me straight???

[xrover]

I am no expert. But here goes.
1) Is your ground plug properly grounded? I always find flat plugs are notorious for the ground ripping out.
2) Was there anything on in the trailer drawing extra current?

Maybe run a larger ground wire directly to the trailer?
And go with a smaller fuse so at least it will blow.

[satch]

Loose, dirty or poor connections can cause the cable to heat up. Since it didn't blow the fuse, I would look into that. I think the problem was in the line between the battery and the fuse.

[greg755]

I got it good to go for the camp out but when I get back I am going to wire in a new harness.

What I think happened is the "charging" wire got mixed up with the "Auxiliary" wire.

So instead of the batteries charging only when the voltage regulator called for it, they were constantly getting a charge from the auxiliary wire.

For now I have disconnected both of these so it should be ok.

I have put the batteries on charge over night, so they should last for the weekend, hopefully they didn't get burnt out when everything went hay wire... I dont have a tester to put a load on them so we will let them go until Tuesday.

Worse case scenario I run out of juice and have to buy two more batteries...

Live and learn, Always double check someone else's (and your own) electrical work...