Basic battery question

[DanSTL]

There is a key, didn’t know but understand it affects power too. Turns out I need a new battery and more…

[rickst29]

Originally Posted by DanSTL

Lots of detail there, so are you seeing a third fuse , which I believe you referred to as the funky inside side-mounted battery fuse (it's probably probably a big one)?

Yes. You are pointing at in 'IMG_9164.jpeg', it connects a thicker battery terminal wire on one side of a fuse (or circuit breaker) to a smaller wire on the other side of the fuse.

That wire is possibly the 10-AWG TM provided "12v" battery connection cable (going back to the WFCO 12v load center fuse board). If so, the 'big fuse' was possibly added as a poorly chosen upgrade.
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Do you have a volt meter? If so, you can confirm 12v voltage from the battery into the into the smaller wire, and check the routing of that wire -- please confirm that it goes back towards the TM fridge area.

[rickst29]

Originally Posted by DanSTL

Thanks Rick will text you now, think you’re in Nevada so maybe not too late? I have a voltmeter and more than happy to have a basic 30A but not sure if it needs to be opened.

Before opening, we can confirm that the TM main wire lug on the existing side-mount fuse/circuit breaker has full battery voltage - demonstrating the the fuse/circuit breaker is not burned out. But we cannot confirm that wire reaches all the way to the WFCO panel circuit board (without breaks or short circuit issues) until after we open the TM and go inside.



If the side-mount fuse/circuit breaker (in the battery box) is "open" (burned out, tripped) we will see zero volts on the TM wire lug, even when the wire has been disconnected. Per a post in the Thread, I strongly recommend that we replace that side-mount fixture with a Maxi fuse and fuse holder (size 30A for standard wirse, size 40A for an upgraded TM wire battery-> WFCO at size 8-AWG).

The side-mount lugs press on the contained battery case at two small pressure points, maybe promoting cracks in the battery itself (and later causing acid leaks and failure). But even more fundamental, It can't be seen without removing the battery from the box. With a small Maxi-fuse inline mount, the fuse lies on top of the actual battery, you can see if it's OK by simply removing the top cover of the box.

If you haven't got a max fuse holder (and matching fuse) with wire leads size 8-awg, you can buy and temporarily use a smaller ATC/ANL fuse holder, they're
available from any auto parts store -- but the wire size of the lead wires will be too small (they're typically AWG-10 at best, AWG-12 and AWG-14 are more typical). In AWG wire sizes, smaller numbers are bigger and better wires.

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If the long wire must be replaced, there may be issues with the current routing. My OEM original (2006) was run along a top corner of the street side frame against the frame, next to the the 7-way bargman cable. It came up into the interior behind the fridge, where it was bundled tight and zip-tied with a large bunch of other wires.

In my own case, upgrading to a much larger wire (AWG-4) required a total re-route within liquidtite conduiit. A portion of the liquidtite conduit is clamped to the bottom of the TM floor. It rises into the TM floor underneath the tub seating area, using a liquidtite connector. But my wire supports a large set of LFP batteries, you don't need all of that capacity.

Your wire replacement issue is this: In the case that the long wire is broken somewhere, the current routing to reach the WFCO panel goes underneath the fridge and bathroom sink, possibly also going inside the lower exterior wall behind the toilet before reaching the WFCO from under the bathtub. There are also probably extra zip ties involved, making it extremely difficult to "pull" a replacement wire by using the existing wire as a part of the pull.

There is some kind of wooden box underneath the sink, that may include wire connections which provide for avoiding the behind-the-toilet wall wire replacement. But I've never looked inside my wooden box, I don't know what is in there.

Primarily for that reason, If the 'long wire' is failed with either a break or a short circuit, I will recommend that we pull its replacement along the frame - past the standard fridge-area wire entry, instead reaching all the way back to the tub area. Those portions of the new wire which can't be clipped to the frame, or other existing clipped cables or pipes, will need to clipped into bottom of the frame. You could use clips like these, as long as the supplied brass screws are replaced by short SS screws. https://www.homedepot.com/p/Gardner-...25WA/205588202

The wire insulation will need protection at both sharp-edged aluminum hole edges through the floor (at the wire entry under the tub). These box fitting connectors would be OK for wire safety, but do not provide any waterproofing. You could use a good sealant (3M 4200) to provide that at the inside of the fitting, against the foam interior. (As a temporary alternative, a decent indoor/outdoor caulk could also perform that job).

The wire (stranded THHN/THN2) is generally available in 25 or 50 foot packages at big box stores, but only in wire size AWG-10 (not more than 30A). If you upgrade to AWG-8, you must buy by-the-foot and it isn't returnable. In either case, I recommend purchasing with RED insulation color.

[DanSTL]

I replaced the 30 amp glass tubular fuse just in case even though it looked good, but the flat fuse (20amp) was good so didn’t replace. No change to the situation with electric in the TM which still doesn’t work. Could the brown frayed wires be part of the issue?

[Bill]

Dan -

Lots of pics, lot of detail, complex area. It is like looking at a knitted sweater, one stitch at a time, and trying to determine what each stitch is doing as part of the whole thing.

Big picture? I think that if we are going to unscramble the situation for you, you are going to have to create a sketch of what is connected to what. You don't have to draw the physical placement of the wires, or their physical routing from one place to another. But the sketch does need to show all the wires, all the electrical connections between the wires, all the dead ends where a wire is not connected to anything, and all the devices (fuses, switches, etc) that are part of the whole. It helps if you indicate the color of each wire in your sketch.

Making the sketch is not hard, but it is painstaking. We have a number of electrical experts on the Forum who can decipher your sketch and tell you how everything works. Help us out here, so we can help you.

Bill