DC operation

[Legacy Posts]

Everything that runs on AC works great in the cute li'l Bigfoot, but I can't figure out the operation of the DC system. I slapped a new & fully charged battery on the newly :) painted tongue plate designed for such thangs, and unplugged the AC. Nada. That's all I had to do in the oooold camper, but this seems to want something more. The DC converter-- I think that's what it is-- has a panel that looks like this:

<img src=http://www.fiberglassrv.com/board/uploads/3eac1a4c97ff1elecpanel.JPG/>

but I can't find any info on operating the sucker. I have pushed and pulled the thingie that says "15v" on it, but get no joy. I have hooked it up with the black running to the positive pole on the battery because the Bigfoot info I have says to do it that way. Scary!

I initially set it up with black to neg as is the rule, but since none of the fuses are blown I don't think that caused a problem. Anybody know what I should be doing differently?

Thanks,

Kitty :wave

[Legacy Posts]

look for a switch marked transformer - dc or something similar. in my trillium the switch is just above the converter and it has transformer, off, battery marked on it

[Legacy Posts]

Joe,

Nope. Can't find any kind of switch except that thing marked 15V.

Thanks,
Kitty
:wave

[Legacy Posts]

Kitty ... and this is just a guess, because I am no expert in anything, ok? ... but I'd say that perhaps you have a bad ground on the 12 volt system ... which wouldn't be surprizing on an older rig.

Usually there is a ground wire that runs to the frame somewhere on the trailer. That ground is prone to rust ... and as a result, bad ground means no 12 volt power.

Here's what I don't know ... it's possible the converter (which converts 110 to 12 volt and feeds the system has a separate ground ... yet the 12 volt direct from the battery has a separate ground ... which is bad.

Crawl around under the trailer and see if you can find a wire attached to the frame. You might have to unscrew the wire, sand off a little rust and reinstall it.

[Legacy Posts]

Often times the dedicated ground wire is also fused ... not at the converter, but along the ground wire itself with an in-line fuse. That in-line fuse might be blown.

Other thing you might do ... call Bigfoot and ask for help! Tell them you're the proud new owner of a Bigfoot!

[Legacy Posts]

A quick and easy way to be sure the instructions are right for hooking up the battery cables would be to un hook them, Then use a jumper cable from the negative post to the frame of the trailer.then put a volt meter between the positive post and the wire you think should go on the positive terminal( should read zero volts if you have nothing turned on.) or if it reads 12 volts you may have the wires backwards on the trailer. A lot of people mess up the wiring due to lack of knowledge or odd factory connections. For Example Black has always meant HOT wire to me, White is the negative or neutral depending on AC or DC. The only exception I understand even a little is a pair of red and black for hot and ground, and even that worries me, but I do see it occasionally.
If all is right then take the voltmeter and check the fuse sockets for 12 volts (remove fuse and insert probe into socket carefully, while grounding the other side of the voltmeter.) If 12 is there follow on out to next place the wire terminates, if no power run backwards toward the battery. Also look for skinned wires shorting out to metal along the way.

[Legacy Posts]

Kitty: I agree with Charles if all else fails, call or email Bigfoot Ind. I haven't experienced any such problem with our Bigfoot to date.

[Legacy Posts]

Kitty,

Looking at the picture that you posted of your converter, I don't see a fuse for the battery. There should be one somewhere. My Scamp had an in-line fuse at the battery box on the tongue. I believe you should find one somewhere around the battery. The reason it should be there is in case the wire should short between there and the converter.

The previous post are trying to figure out if you have 12vdc getting back to the converter. I agree with the way you have it hooked up, black + and white -. If you could find where the wires are hooked to the converter and test and see if you have the 12vdc, you would have a better ideal of what is wrong. I would unhook the AC plug and only check the 12 volt DC. If you need to take anything apart to get to the wires. Make sure that you disconnect the battery first. Then you can reconnect it long enough to test for voltage. If you don't get the voltage then the wires are open going to the battery. If you have the voltage then the contactor is probably bad in the converter. At this point you can change the part or find where the wire is open.

This isn't as hard as it may sound. Just do it a step at a time.

Let us know how you make out.

[Legacy Posts]

I've got all these good comments printed out now. I hope to try to work my way through some test on it tomorrow.

Yes, there is a dealie on the tongue that needs investigating. Ypu're probably right that it's a fuse. I'm good at frying them!

BTW, when you are connected to shorepower, does the AC typically charge your battery?

Kitty

[Legacy Posts]

Yes

[Legacy Posts]

Only if it is a converter / charger.
and not just a converter.

[Legacy Posts]

There are different color conventions for AC and DC wiring in North America:

1. AC wiring:

Black is hot (one phase in two-phase system)
Red is hot (opposite phase in two-phase system)
White is neutral (neutral point in two-phase system)
Green is ground

2. DC wiring:

Red is positive (+)
Black is negative (-)

Most (all?) modern automotive systems and most (all?) RVs use a +12VDC system where the negative (black) wire may be fastened to a common chassis/frame as a return to the battery (aka negative ground return)

But sometimes, esp in 12VDC wiring, the color conventions are ignored and the wire colors are whatever the manf or owner happened to have on hand...

Pete and Rats

[Legacy Posts]

There was indeed and inline fuse-- and I'd been staring at it all along. It dawned on me today that the shiny black wide place in the wiring might hold a fuse. It did, and after that it was a quick fix. I got DC power now.

Thanks to all for great help.

Kitty