Intermittent power problem

LauraC

Hello fellow T@Gers ... I hope there is an electrician on the forum. I did read the post about RV electrical systems - excellent. However, reading that did not solve my problem. (2015 T@G Basic) It's a long story. Please bear with me. I believe my camper got a jolt of over or under power at a campground last May 2019. There was a Bump and Jump vendor at the Town Square where I was parked and his generators actually blew out the Town Square hot water heaters so I know there was an issue with power. Also, I had to plug into a 20 volt supply as there was only 1 plug for 30 volt and someone else had taken it.

Day 2 at the campground my water pump and refrigerator both stopped working. No power. Eventually the water pump started working again - intermittently - but the Norcold would not power on. No error message - just no power.

The rest of the summer last year the water pump and Norcold both had intermittent power supply issues. I eventually started bringing a Yeti and gave up on the Norcold. Last fall I had the RV dealer look at the converter and Norcold. They concluded both were fine and said I needed a new battery. I was relieved - that's an easy fix. But, first trip out this year - last weekend - with my brand new battery and the issues with intermittent power supply continued.

The strange thing is - all was fine for about 24 hours. I was plugged into shore power at the campsite and water pump and Norcold both worked fine. Then, no power to either. I turned off the power at the post to re-set everything and about 10 minutes later both water and Norcold had power. That lasted for 5 minutes, then both the water pump and Norcold lost power. (during these events the lights, fan, power outlets all continue to have power and work just fine) Turns out the campground host was an electrician. He suggested I check the battery to see if it was getting a charge from the converter. I happened to have my voltage meter - battery was at 13.65 so the converter was working. I then kept everything off for awhile and sure enough, when I tried both a little later they had power. At one point, while both were running, I was in the camper and heard the converter fan running which I thought was a good sign. I had the cover off and while I was there the converter fan stopped, a red fuse light came on and both the water pump and Norcold lost power. I have tried replacing fuses and that does not help. I wiggled the red lit fuse and the light went out.

Later the water pump started working again so I could finish the trip with running water. I had given up on the Norcold and kept ice in it for the remainder of the weekend. I talked to the camp host about all of this - he said it sounds like a short in the wiring behind the fuse box/converter. He said after there's been a surge (which may have happened at the Town Square campground last year) wires will expand and contract which could be the reason for my intermittent power supply. He said the fuse light turning on and then off is another sign of a wiring issue.

Now the problem is finding someone willing to check out my wiring system. The electrician said it may be hard to find someone with the patience to diagnose an intermittent problem like this. I know I may get no takers on this one - but thought I would post in case someone has an idea about what's going on. Once fixed I will buy a surge protector for sure!!

Thank you!!

WilliamA

Electrical troubleshooting is one of the most linear, straightforward kinds of automotive-mischief investigations. The downside is that it's easy to overcomplicate the problem. First, don't assume that the problem was "caused" by any particular event. It showed up. That's all you need to know. Second, if the problem is evident in multiple places at once (refrigerator, lights, etc) it's more likely that the problem is in a single, common circuit, like a ground wire. I'd start with the battery ground (is it loose?) And follow the primary ground wire from the battery to the converter. Chances are very good it's just a loose wire or connection. If that's all good, then do the same thing with the battery positive wire that goes from the battery to the converter. It must be within one of those circuits or it would not effect multiple individual circuits.

It's possible (but unlikely) that overvoltage was the problem. Those kind of events tend to be obvious, as in, smoke and dead shorts, not intermittent problems. My money is on a loose connection in either the battery ground or battery positive circuit between the battery and converter.

As an aside, I don't have a surge protector in my trailer for the same reason I don't have one in my house. In the event of an overvoltage spike, most won't do much to protect anything. The vast majority of voltage related damage incidents are caused by undervoltage, not the opposite. When voltage goes up, current (amperage) drops dramatically. (Ohm's law) When voltage drops, amperage increases exponentially. The most common cause of appliance damage from electricity is from high amperage and arcing. When an arc occurs, amperage and voltage can instantaneously increase 10 or 20 times normal as the field collapses (that's how ignition coils work). The best money you can spend on electrical safety IMHO is replacing the breakers with arc-fault breakers. They are different than ground-fault breakers and are stupidly expensive. They are getting more common, even becoming code, for household applications.

For lightning protection, I recommend being somewhere else....Or investing in a good Faraday cage, to put the tow vehicle and trailer in. That's several million or more volts that just jumped an arc several miles long. It will have zero problems jumping the 1/4" gap in your lightning arrester/surge protector. Just unplug everything and wait it out.

WilliamA

LauraC

Thanks WilliamA ... I will attempt to find and follow the wires you mentioned. I will save a lot of money if I can figure this out on my own, that's for sure. Thanks also for your thoughts on a surge protector. Interesting. So, the water pump and refrigerator are on two different circuits?

WilliamA

Yep...

JamesDow

Interesting that you sound like you have issues both on shore power and battery, and maybe only some circuits.
Is that your thoughts?
Isolating the problem is key. What exactly are the circumstances when it occurs?
[12 volt or 120 volt] - [Using camp site power or anytime] - [All circuits of just some] - [Battery cutoff switch on or off]
I would go to the website of your model of converter and download the manual. (Maybe 13 pages) My converter is a WFCO Model: WF-8725. If it is WFCO, I found them to be very knowledgeable and helpful.

• Check the wires at the battery as suggested.
• I would buy a packet of fuses and replace the 4 or 5 fuses. (you need some around anyways)
• Click on and off the 120 volt circuit breakers. (may not do a darn thing, but it cant hurt)

Good Luck

https://wfcoelectronics.com/wp-content/uploads/2019/06/8700-Series-Manual-web.pdf

LauraC

JamesDow ... thanks so much! You pose some good questions. I recall that last summer I camped using my Zamp for four days and I don't remember an issue with power. Of course, I don't use the NorCold when I'm boondocking - but I don't remember a problem with the water pump and the two issues usually happen at the same time. So maybe the problem is when I'm plugged in at a campsite. I just checked her out now (I call her Lil Nell) and, not being plugged in, both the water pump and NorCold powered up. I have replaced a few fuses but not all of them. Every time I check, the fuses look fine. But good idea to replace them all again. Can someone send me a screen shot of the battery cut-off switch? I don't know where that is. I haven't ever put my eyes on the battery fuse, either. I need to get to know my camper better, I guess. I have a call in to the RV dealer as I wonder if this is all too much for me. I have no idea how to trace the wire from the battery to converter - won't that be encased in some sort of plastic shield or tube? But, I will try. If I ever get a call back from the dealer I will tell them I'm working on it myself for now.

JamesDow

LauraC;
Attached are photos of the battery shutoff and the battery fuse.
If you unplug from shore power and the Tow Vehicle (TV) and have the battery switch turned to ON. All of your trailer LED lights along with the Norcold and water faucet should function. If so, the fuse is good and no real need to check. (I have not had a problem with this fuse)
Note the position of the battery cutoff switch. I marked mine with the word OFF to assist in understanding the dial placement.
With the switch turned to OFF, the lights, etc. will not work, unless you are hooked up to shore power or you are connected to your Tow Vehicle with a round seven way plug. (The round plug is what feeds the turn signal and brake lights of the trailer and provides power to the trailer to help charge the battery while your Tow vehicle is running.)

To open up the black battery case:

• Note he position of the wires that exit the top of the case.
• Unstrap and lift the top of the cover.

Once exposed, you will see the wires hooked up along with the fuse. When you replace the top of the case watch the position of the wires, so they are not impeding with the top of the case to properly close it.

You likely do not need an expert to help track down the problem. Someone who has had a trailer before may be the right call.

Good Luck
—Jim

LauraC

Thanks again, James. I haven't had time to work on this project but just strapped on a headlamp to take a look. I learned something new. My T@G is a 2015 and I believe that's the first year they made them. My camper doesn't have a battery on/off switch. Thanks for the photo with diagram of battery fuse - that I do have. But, as you said, since everything works at times the problem can't be a fuse or the problem would be continuous. The RV dealer repair guy agreed it could be an issue with the ground wire. He said they're accessible. But, I just checked the wiring from the battery - and looking at the photo you posted above - the wires are wrapped in plastic so I can't see any obvious place to check for a loose ground wire connection. My husband thought I should wait until daylight - ha! He's right about that. I hate to be a pain - but how might I check for a loose ground wire? I was hoping to just see a black wire connected to the frame somewhere. No such luck.

WilliamA

LauraC,

If your trailer is similar to my 2017, there's a junction box on the inside of the left frame rail sort of under the left door. Remove the 2 screws holding the cover on and you'll see a bunch of connections. Poke around in there to see if anything is loose. There's no need (yet) to start stripping back the plastic wire loom.

After checking the junction box, carefully examine the crimp-on connectors for the wires that attach to the battery. Give them a wee "tug" to see if the crimp is tight.

If your trailer is like mine, there are a number of "Scotchlock" connectors. (The original "semi-conductor") that will need looking into. I don't remember any on the ground circuits of my own trailer but they are notorious for bad connections. I also found some badly crimped splice-connectors in my trailer, mostly in the light circuits, and replaced them.

As someone else said, I'd also replace ALL of the fuses. It's easy, cheap and simply rules out a sketchy one.

Keep digging....

WilliamA

LauraC

Thanks, William. I just checked the wires in the box and the connectors, everything looks fine. My friend's husband owns a local electric business. I think I will ask if he might send someone over to take a look. Of course, everything is working fine at the moment.

LauraC

Hello all ... for anyone following this thread I have an update. I talked to a very nice guy at WFCO regarding my intermittent power problem. He said it sounds like a short circuit. I commented that people have told me the water pump and refrigerator are on two different circuits - so is it possible I have 2 short circuits? He said there is no way to know which appliances are on which fuse/circuit unless you check. He said he has been to a lot of RV factories and has learned that the technicians putting the "coaches" together will connect appliances to different circuits on any given day. So, I turned on the water pump and started pulling out fuses until the pump lost power. Fuse #2 did the trick. Then I did the same thing with the NorCold - no power when fuse #2 pulled. So, it appears I have a short behind that 2nd fuse. Now I just have to figure out how to locate the bad wires behind the converter/fuse box. Progress!!

LauraC

I found (stole) the attached T@G wiring diagram from a post by "Jake" in September 2018. He has both the refrig and water pump on fuse 2. Anyway, I thought of another friend who might be able to check the wiring for me. At least I have narrowed down the problem. I don't dare do it myself. (My electrician friend said he doesn't know anything about RV wiring)

LauraC

Another update. I found the ground connection - on the frame below the water intake and power plug. It looked fine. I called a mobile RV repair business - they were reluctant to come out and deal with an intermittent power issue but did call WFCO. The person they talked to suggested tightening the connection on the 2nd fuse. I did that. Then I powered up the Norcold and it ran fine for 25.5 hours. I just turned it off. No problem. So, it's possible a loose fuse connection was the problem, and the problem is solved. But, I wonder - is there a difference in the voltage of power coming out of the house vs coming out of the pedestal at a campground - with the pedestal switch on 30 Amps?

LauraC

Oh, and I also put a new fuse in number 2. I had replaced all the other fuses last summer.

WilliamA

LauraC,

Glad to hear you have it on the run. Those can be a head-scratcher. But the upside is your new familiarity with voltage bits. "Bird by Bird" as the poet says.

As to your voltage at the pedestal question.... You generally have to take that with a "poke and hope" attitude. The "grid" is a big place. I personally don't worry about it at all. A good bottle of wine and aged cheese tastes just as good.....

In the dark.....

WilliamA

Sharon_is_SAM

@Laura - the Campground pedestal and household power are both 120v. Besides an EMS, you can use a non-contact voltage tester (NCVT) on the pedestal before you plug in to determine if the pedestal is sound.

LauraC

Thanks William .. I had to look up "Bird by Bird" ... sounds like a good book! and a good way to tackle seemingly impossible projects.

Thanks, Sharon ... I've concluded the problem is probably not related to an electrical issue with the pedestal. Not sure if I really need to invest in a voltage tester or surge protector but I may.

I spent two hours today reading (for a second time) the RV electrical system link that Mike posted, along with manuals for the NorCold, the WFCO and my T@G. I get that my T@G is dependent on the battery system - except for 120v going to the WFCO and 120v outlets. I concluded that there are protection systems for all of the scenarios I thought could have caused the intermittent lost power problem and there are no signs of a power surge, blown fuse, short circuit, etc. I also concluded the issue is between the WFCO and the NorCold and water pump. That narrows it down to the fuse as there's no way to check out the wiring farther back without pulling apart the nice wood, cauking, etc. And, I really doubt there is a problem with the wiring. So I'm going with the loose fuse connection. Also, since WFCO came up with that idea they must have heard of this before. My next campground reservation isn't until the end of July but I'll know then if the tightened fuse did the trick. I will post again.

LauraC

Just finished a two night camping trip and for the first time in 2 seasons of camping - no electrical problems!! the water pump and Norcold operated perfectly. So, the problem was a loose fuse. I wanted to post an update in case anyone is reading this 5 years from now looking for a solution to the same problem.

JamesDow

Nice to have a solution .. finally.