New battery, but no juice. Am I missing something?

[tmsbandman]

1992 300BH. Was sitting for a long time on shore power before I got it. The battery was very old. Replaced battery, disconnected the 110AC, but the lights in the TT don't work. Ideas? I checked fuses already.

Just confirming: positive connection is the one that passed through the frame alongside the gas line, and negative passes through with the 7 pin cable? That's how the old battery was wired.

Thanks

[tnchuck100]

Not having a 300BH I cannot relate to the gas line and 7-pin cable references. However I will pass this information to you.

The negative battery cable should attach to the frame. Usually close to the battery box. It is usually white. The positive wire should have an in-line fuse near the battery. This wire is usually black. There may be a couple more wires on the positive terminal as well. The break away switch for the brakes and a tongue jack wire if so equipped.

There are also two fuses (usually 30 amp, green) in the converter. One for the main and one for reverse polarity protection. These are in addition to all of the circuit distribution fuses.

Hope this helps.

[tmsbandman]

Hmm. No ground attachment near battery. I have one black wire (which includes an inline fuse) and two white. Is it possible that BOTH white wires are negative? I will look for the fuse on the converter, but it works fine on shore power. Thanks for the help

[Threebutchers]

Originally Posted by tmsbandman

Hmm. No ground attachment near battery. I have one black wire (which includes an inline fuse)

That's the positive connection - check the fuse

Originally Posted by tmsbandman

and two white. Is it possible that BOTH white wires are negative?

Pretty darn possible....unless someone did a mod and used the whatever color wire they happened to have on hand. Trace them back if possible

Originally Posted by tmsbandman

I will look for the fuse on the converter, but it works fine on shore power

Your converter produces 12+VDC from 110V shore power...can still be a blown reverse polarity fuse.

Good luck! Let us know what you find!

[tmsbandman]

I took a look at the converter. No fuses on to outside. There is a fuse panel mounted near it, but all fuses are good. Converter is a MagnaTek 940-2. Their manual doesn't show any internal fuse. Trying to trace wires now

[Threebutchers]

Is this your manual????

http://www.parallaxpower.com/775_900...ual.pdf‎

[tmsbandman]

Can't get the link to work. BUT.....Got the electrical going. The "mystery wire" was going nowhere. Apparently a previous owner had needed 12V near the door. Anyway-black to + and white to - and all is well. Weird thing though: Last night I was running interior light on shore power without even having a batter on the TT. Now the lighting ONLY works if connected to the battery. Did I screw something up?

[RoyBraddy]

You need to have a multimeter and check the battery terminals without shore power "on" which should read 12.6-7VDC if the batteries are charged up. Then connect shore power "ON" and the battery terminals should now read 13.6VDC. This will tell you the on-board converter/charger is charging your battery as well as all of the fuse and wire connections between the converter/charger and the battery are good.

What you are describing now is the on-board converter is not working. It plugs into 120VAC inside your Power Distribution Panel and its 13.6VDC output feeds the 12VDC side of the Power Distribution Panel. The Battery also feeds the 12VDC side of the Power Distribution Panel.

Here is a simple block electrical diagram of a typical 30AMP Trailer - maybe this will help identify what goes where...


You are probably finding out why the previous owner has had some wiring disconnected - something failed and didnt get fixed...

Just keep in mind if you are going to tow your trailer that it must have a BATTERY 12VDC source to provide power to the trailer BRAKE MAGNETs in case the trailer becomes disconnected when moving down the road. This is a DOT law if you have electric brakes installed on a moving trailer.

just my thoughts
Roy Ken