I am replacing my battery today in the RV... it's lasted real well...was installed in 2007. Now has 3 bad cells. But that isn't my question. I spot tied the "HOT" lines that were on the battery before removing and my question is: Is for there ANY rhyme or reasoning behind the DC wiring as far as colors go...... I've got red to Plus, red to Minus and the same for white. Is there ANY way to REALLY ohm out the wires and tell what is actually a hot lead and which is supposed to be ground? On some of these wires, I can connect to a good RV ground with a clip lead and touch some of the wires that were connected to the Minus terminal on the old battery and that's fine. Problem is there are SOME that were connected to the Minus terminal that do NOT show continuity when I touch to a good RV ground with the other lead. Good news, these also did not show continuity to the + terminal either. It's a nightmare....

Any ideas gentlemen and/or ladies? Please don't tell me to simply put 'em where they were..... I'm scared to do that.

 

Unless you’re having a specific problem that makes you suspect the wires are hooked up wrong, just put them back where they were.

I know it’s confusing but there are a lot of separate electrical systems on an RV. Some require 24 volts and some require 12. Some are wired to run off the batteries and the generator, and some are wired into switches that are normally in an open/neutral state (which may be why they don’t ohm out).

Unless you want to unhook each wire one at a time and then start flipping switches and walking through the RV trying to figure out exactly what it powers, don’t stress about it.

 

Colors can vary. By convention whites are normally grounds and reds would be positive. Do you have black? How many batteries? How many total wires/ Yes you can verify positives using a volt meter, not ohms. You don't have anything that is 24 volt, don't worry about that.

Steve

 

As a tech at an independent shop that services everything from chainsaws to semi’s, I always like to learn new things, so think of this as more of an inquisitive child rather than someone challenging your knowledge.

I have serviced a few RV’s (basic maintenance on engine and generator, changed batteries, brake work, etc) but don’t have a wealth of knowledge about them in general.

I’m curious how you can know nothing is 24 volt when you don’t know what year and make the RV is. The OP states there’s seemingly opposing wire colors hooked up to the terminals (white to positive, red to negative) so to me that’s an indication there could be a few circuits that are wired in series to the batteries, meaning they would be pulling 24 volts.

On that note, I realize the OP doesn’t specify changing multiple batteries, but the experience I have with them, there’s always a battery to start the engine and then there’s at least one additional battery for auxiliary systems. These batteries are usually connected to each other somehow, if for no other reason than to be charging from the alternator and/or generator.

And....GO TEACHER GO!!!

 

There is nothing in an RV that requires 24 volts and there is no 24 volt charging system, that I have ever seen. The OP has a very basic electrical system in his Arctic Fox fifth wheel as noted in his signature. He may have two batteries, but they are either two 12s in parallel or two 6s in series. When the batteries tie together on a motorhome to feed off the alternator, they connect through a relay in parallel, not series.

Even in the big diesel pushers I serviced did not have 12s wired in series nor do any of the towables. The genny, if he had one is 12-volts. For 30 years I was the lead tech at three different dealerships, I can't do a chainsaw or a semi, but I can wire RVs and have done it from scratch when folks disconnect all six batteries in a diesel pusher and don't know how to put them back together.

I was not trying to step on your toes. I just didn't want Bud to possibly get more confused than he already may be. I think you initial advice was spot on. Unless there is a reason to think something is wrong, it probably is just fine and even if he makes a mistake, there is darn little that can happen and I have had more than one customer wire their batteries backward. Folks think something will explode, but the most common thing that happens is something or a lot of things don't work.

Steve

 

Fair enough - thanks for the lesson.

One drawback to viewing this site on my phone is it doesn’t show the signatures so I couldn’t have known that was his RV without looking at this thread from my laptop.

I appreciate the variety of experience I get at my shop (I once had the fun task of troubleshooting a 1968 Harley Davidson electric golf cart) but it often leaves me in a position of giving very general advice rather than knowing the specifics of any particular vehicle. I was caught on the 24 volt comment because a few months ago I replaced 2 deep cycle batteries on a customer’s RV and it did have a jumper from the negative on one battery to the positive on the other. I thought they were 12 volt batteries but I’m not gonna trust my memory on that - my boss said replace those batteries, so that’s what I did.

I didn’t think you were stepping on my toes - I just couldn’t help but notice your screen name and jump on the chance to hijack this thread.

 

Thanks folks for all the words.....but just to let ya'll know that I found the problem with the help of the manufacturer, Northwood Manufacturing. I neglected to say that I had thought I had reconnected everything correctly-and I did, come to find out. My problem was the spot tie I had put around all of the + leads to separate + for - broke as I was removing the old battery. After I installed the NEW battery everything seemed to work in the RV EXCEPT the main slide. It was then I panicked thinking I may have done something wrong and I posted the original post up above.

After a day of no responses I called Northwood and got the info I needed and found I had simply "LOST" the hot lead to the main slide control box. Northwood did help me determine what wires were what tho and it helped a lot ! With the help of a 12/6 v probe (the kind with a sharp pointed end and a light in the other) I opened the Slide Control panel and found no 12v at the point where there was supposed to be. Tracing that hot lead back towards the battery (wires through the body wall) I finally saw I hadn't connected that wire to the battery !! It had been lost in the rats nest of wiring. Simple end to a panic situation. BTW, I found out that as I age I am much quicker to doubt myself when something goes amiss. I must remember to us the saying of "KISS". Hope you all know what that is.

Another thing you young guys obviously don't know (or remember) when it is said that when you "OHM OUT" wires, you are actually doing is checking resistance in that or those wires. What is the symbol for resistance Steve??

 

I know the symbol, but my keyboard doesn't.

The reason I suggested voltage is that is a faster way to check the "hots" and I thought that was you point of confusion. Actually this type of problem is one of the easiest one to troubleshoot because, as you discovered, the solution is so often right in front of us. Operator error, as the industry calls it, it perhaps the #1 cause of problems for all of use. Once you understand how one fiver is connected, you basically understand all of them so Bud, the next time it is your call!

And don't go calling us old guys old!!

Steve

 

Hey, here's one I'll share with you all. We keep our fifth wheel at Ocean Lakes in Myrtle Beach and wander in our truck camper. So last time we were at Myrtle, they were going to come pick up our fiver and put it back in storage, hit the slide switch and nothing. The slide is on rails underneath with a motor in the belly. I like this system much better because I can troubleshoot it in minutes, the problem was the only tools I had with me were in my "first off the truck" diagnostic bag. Just really basic hand tools, but I did have a meter. Pop the switch out and discover (duh) no power at the switch, but the fuse is good.

What to do, what to do? I know I could go underneath, cut a hole in the belly and ratchet the slide in, but that takes an eternity and is such a pain the manufacturer that thought it up should be shot. Fortunately, however, most manufacturers group the switches and my power awning switch was right next to my slide switch. I had some 16 ga wire (too small to carry the slide motor load for long, but enough to carry the load briefly). so with my wife pushing the button if you will and me holding the jumper in place, we ran the slide in a few seconds at a time. Do it too longs and the wire gets hot, melts the insulation, ouch. On the next trip I had to run new wires replacing what the mouse had chewed!

Morale here is even when it seems like a tragedy, it almost never is.

 

Nice work there old timer () - there is nothing like common sense and a lot of experience !