Connecting batteries in 5th wheel

[sfward]

Hi Hope this is the right place for this. if not, my apologies and please redirect me.

To make a short story long, I have a 96 Wilderness 26ft 5th wheel. Practically new. Previous owner maintained it religiously. My brother-in-law pulled the battery to charge it. However he neglected to pay attention to what wires went where. When I opened the box to install it I noticed it was rigged for a two battery system. There are four leads and two sets of jumpers. I did a continuity test on the leads to ID the negative lines. For the record, I did this by connecting the meter ground to the frame and then the positive probe to the negative lead. When I got tone I knew I had the right wire. Additionally I traced one of the leads to the ground connection on the frame. I traced another lead I was sure is a positive and found a 30amp in line fuse. That has to be a positive.

So, being fairly certain I had the right wires I connected a battery. Nothing. I tired the other wires. Still nothing. I made absolutely certain I was not reversing the polarity. It was working when my brother-in-law used the trailer. he simply ran the battery low which is why he pulled it out to charge.

I know how to put the other batter in parallel once I get the wires connected for power but until I can get the original battery (even tried the new one) working, I'm just spinning my wheels.

I'm including a photo. The two top wires with yellow connectors are positive. The two lower wires with red connectors are negative.

Any help offered would be greatly appreciated.

[egwilly]

Is your battery disconnect on?

[Bob_C]

Check the converter rev polarity fuses.......they can blow without being hooked backward....mine has 2 30 amps ones in the front behind the door of the converter

[sfward]

Thank you both for your reply.

EGWILLY: Not sure what you mean by battery disconnect but I'll gladly check that if I know what I'm looking for.

Bob: Converter reverse polarity fuses: Where would those be and how do I check?

BTW, don't know if this helps but it had only one battery in there before and worked. Just ran low. Now with it out and no one knowing how it was in there originally ....well....here I am.

Oh, last thing. If it helps, my camper is a '96 Wilderness 5th wheel approx 26ft.

[twinboat]

The converter would only affect charging, not operation on battery.

I would say the red wires are pos and the black and white are neg.

Put on the ones you confirmed are ground and fused. See what happens. It may be your jacks, if you have electric.

Are you using 12 volt batteties or are they 6 volt and need to be wired in series ?

[shiggs68]

If you have access to shore power, you can plug the RV in and you can measure the voltage across the wires until you find the pair that is charging the battery. That and what you already know should solve the problem.

[sfward]

Twinboat: It has electric jack but nothing is on. I tried each set of wires individually (as pairs) but still nothing. Not even spark when grazed across the battery terminals.

To be clear, when I did the continuity test the ground wires should sound a tone but get nothing from positive, correct?

Lastly, as said before, I did trace the white wire to the connection on the trailer frame. One of the reds with the yellow connectors has the in line 30amp fuse. Has to be the positive.

Each combination I tried I'm still getting nothing from a battery. These are new deep cycle marine 12v. It WAS working until they ran dry. If only my brother in law paid attention. Just goes to show, if it's yours and you don't want it messed up, you had better by golly be the one tearing into it...

[sfward]

Hi Shiggs: I just bought a new generator so if I connect that up I should be able to check which line is which?

FYI, I'm not an electrician. What tests I've conducted to date were given to my by much more experienced and wiser people than myself. I'm just some schmuck with a trailer trying to figure it all out.

So, if you can tell me what lines I should touch with my meter probes and what I am looking for insofar as readings that would be helpful.

[Bob_C]

The polarity fuses in mine are located where the circuit breakers and 12 volt fuses are.......and the wires running from the battery positives go to the converter.....but, the wire going to the jack can be direct from the battery and has a fuse in it....saves running extra wire..and you're certain the battery has power....just ask'n bout that..

[sfward]

Hi Bob. Well I did isolate the white wire are the ground. Traced to the the frame. The other red has that 30amp fuse to pretty sure it's the positive lead. Both batteries are new. The breakers weren't tripped. Scratching my head on this one. You'd think there would be only a ground and positive lead in there then the extra wires that had a connector on each end were for setting up a parallel system. Not sure why I have four wires coming out of the battery box. The other ends go into the trailer so not sure were they call home. with the exception of the white ground of course.

[Bob_C]

And you've tried hooking all 4 up?...2 negs and 2 pos.....to one battery.....should also be automotive style blade fuses....I'll go take a pic of my power center...

[sfward]

Bob: Yep. Connected all four. Assuming toning out the grounds was the correct thing to do. But then i did trace the one ground to the frame so pretty sure I got that right and the positives did not tone. Tried just one set. Then the other and then combinations of the four. A different positive with a different ground etc.

Is there a master switch or something in the trailer? I had an older 5th wheel that had a light switch like button you had to flip on to allow for battery use but I haven't seen anything like that inside for this one.

[wingnut60]

And thru all of this, you got no sparks? Not trying to make a joke, but seems to me there ought to be some indication of the battery(s) trying to make the connection to something...
In my normal putzing around, I either get small sparks when connecting the wires correctly, or lots of sparks if connecting wrong. This is the extent of my electrical knowledge, sorry.

[Bob_C]

This is mine....the red or orange at the bottom, just to the left of the fuse row, are the rev polarity ....for me, I find a test light to be quicker, then use a meter to fine tune...