Inverter issues, need help identifying source.

Fasttimes · 11-18-2018, 04:46 PM

My Ultralite TT is all of sudden not working on 12v power. The coach only has power when connected to shore power. The inverter seems to be charging the battery, but just not using it when I need it with no connection. I see no blown fuses and have switched back and forth all of the circuit breakers.

From reading around on the web I've seen a lot of comments to check on the ground connection to the frame of the coach. I removed the thick white ground wire going from the battery to the frame and took a dremel and really cleaned well the connectors on all ends as well as where the wire is screwed to the frame but no change.

The inverter is a WFCO WF-8955PEC and seems to be common. How do I test that 12v power is getting to the inverter? I see the end of a thick red cable posted to the circuit board, but not sure if that is for 12v or the shore power line?

There is also some type of junction box, but I see no issues looking in it, but not sure really about it.

bfliflet · 11-19-2018, 06:14 PM

For clarification, the model you mention is a converter/charger (AC->DC) which is meant to charge a 12v battery. This model is not an inverter (DC->AC).

When you say it 'all of a sudden not working on 12v power', are you saying it previously worked on 12v power? Specifically, were the 120v appliances (i.e. microwave and AC powered TVs) running while not connected to shore power?

I'd be surprised if your TT came with an inverter from the factory unless it was installed after the fact. I just recently replaced my factory charger/converter with an inverter/charger/transfer switch and mine is a 2018 2108DS.

Morich · 11-20-2018, 08:01 AM

Not to be a worry wart but do want to mention something folks might miss. I sense that you are new to working on battery and that can be dangerous if we don't give them some special attention!! Not to scare you but to let you be aware?
Be very careful of making sparks as there is a gas coming off batteries when we are charging them and if you get a tool touching the positive post and something grounded like the frame, it can do a massive burn with lots of bad things. Don't get careless just because it's "only" a battery!! Enough said and you may already know that>>>Sorry.
But one of the first things when owning an RV and wanting to find some problems might be to get a meter. Harbor Freight might be good enough but they are almost "required" to do the troubleshooting and testing things like batteries.
Nice job cleaning the connections but now you need to move to the "pro" stuff like a meter and it lets you actually measure the voltage going in and coming out of things.
Get a digital meter and put the black wire on a ground like some part of the frame, etc. and move the other wire from point to point along the path like the in and out and you can see where it stops!
It will also let you look that the battery is full, half full or "I'm not getting any lights today"!!! Handy things to know. Good luck and keep working it, until it comes clear.

Added note? The meter will give you a really handy way to look for blown fuses. In the picture of the power center, there are fuses on the right side (yellow, red, black with numbers?) You can pull them and look for burned ones but sticking a test probe in the small crack will let you test without pulling it. Look for voltage on the left and it should be the same on the right! Comes in/goes out! If not pull that fuse and look that it may be burned on the side. Quicker, easier and safer than fussing to pull and then maybe not easy to get it back.

Fasttimes · 11-20-2018, 08:16 AM

Quote:

Originally Posted by bfliflet

For clarification, the model you mention is a converter/charger (AC->DC) which is meant to charge a 12v battery. This model is not an inverter (DC->AC).

When you say it 'all of a sudden not working on 12v power', are you saying it previously worked on 12v power? Specifically, were the 120v appliances (i.e. microwave and AC powered TVs) running while not connected to shore power?

I'd be surprised if your TT came with an inverter from the factory unless it was installed after the fact. I just recently replaced my factory charger/converter with an inverter/charger/transfer switch and mine is a 2018 2108DS.

Thanks for the clarification, converter it is. Regarding working before, yes, when there was no shore power the battery would operate the lights and slides as well as be able to spark the ignition on the gas option on the refrigerator. Right now, without a connection I get nothing.

powercat_ras · 11-20-2018, 08:23 AM

Down in the center bottom of the junction box you posted a photo of, is a circuit breaker. Look for a button on one side of it you can push in to reset it , if it has tripped.

That might be your issue.

BobC · 11-20-2018, 09:45 AM

Quote:

Originally Posted by powercat_ras

Down in the center bottom of the junction box you posted a photo of, is a circuit breaker. Look for a button on one side of it you can push in to reset it , if it has tripped.

That might be your issue.

Check the 40a fuses and double check your polarity hook-up, especially if you've disconnected and re-connected your batteries for any reason (I see a warning label in your photo). You may also find another separate breaker-like thing or possibly even a fusible link (Google it) mounted somewhere near your batteries.

cbeierl · 11-20-2018, 08:44 PM

If you are getting 12V (DC) power to run lights, etc. when connected to shore power but not when disconnected that would imply that your converter is correctly supplying 12V (DC) power (converted from the incoming 120V (AC) power). However, with the shore power disconnected the converter is out of the picture and 12V (DC) power must come from the battery--if you're not getting any then the battery is switched off, disconnected, or bad.

**creativepart** · 11-21-2018, 08:19 AM

Quote:

Originally Posted by cbeierl

If However, with the shore power disconnected the converter is out of the picture and 12V (DC) power must come from the battery--if you're not getting any then the battery is switched off, disconnected, or bad.

Sounds right to me.

Morich · 11-21-2018, 08:32 AM

This sort of situation is where I often advise waiting and thinking carefully before we jump inot changing out equipment as it can be a very expensive mistake. When I read the first post, I thought I saw several sings of the poster being new to the electronics troubleshooting and that makes it very easy to make mistakes. Nothing wrong with being new as we are all there at some point, but we do need to be honest with ourselves before we make mistakes. The poster is correct to be asking questions! Good place to start but it is to easy to take the first answer, if we are not slow to jump. The first answer is often not the best answer so we need to move slowly and look at the situation until WE understand it as the internet is full of the wrong info and that means we need to thoroughly check any information we get?
I advise getting a meter, learning to use it and then checking before doing the wrong thing that may simply be a waste of time and money.

Fasttimes · 11-21-2018, 08:52 AM

Ok, I think I've narrowed it down to the junction box area. The converter is sending 13.7 there on the top positive connections, but the bottom positive connections are not getting any power to the post. Only if I connect the battery up do I get a reading which is 12.7 from the battery to that post. If I remove the connections to the battery and test the lines to the battery they do not have any current, so I was incorrect and the battery is not charging.

Am I missing something on these junction boxes? Could it just go bad and not be sending power to the second bottom post?

Morich · 11-21-2018, 10:19 AM

I'm not able to tell from the pictures but power cat mentioned that as being a breaker or fuse. Terrible place to locate something that might need attention as it is pretty well buried but can you tell if that is a fuse or breaker? If so, having power at one end and not the other is a definite problem. There may be a way to push something to restore or it may need to be replaced if a fuse.
Side issue info? The big black cable from the right is likely to be shore power cord, the top section of white wires is ground or "common" with no power.
disconnect power from shore and then pull/dig in carefully to see what you find?
a better layout would be to put the fuse outside and not in a junction box where it is hidden. I'm second guessing myself on some of that as having the shore power cable and you finding DC doesn't sound right!!!

BobC · 11-21-2018, 10:39 AM

I can't tell what's connected to it but could the black thing in the middle (with the yellow connectors at the top) be an auto reset circuit breaker? I recall something like that in my last TT. If so, it may be bad or may be tripping for a reason. Just make sure both your shore power and battery are disconnected before poking around or trying to remove it.

If it is such a breaker, with all power removed, there should be continuity between the two posts. If there isn't it's bad. Even if there's continuity it could be tripping prematurely. They're inexpensive so you might just want to replace it, just remove it and take it to the auto parts store. If you do and the replacement trips you need to do more trouble-shooting. Hopefully replacing it will put you back in business.

These images might help you determine if it is such a breaker:

https://www.google.com/search?q=auto...w=1164&bih=499

Fasttimes · 11-21-2018, 10:46 AM

Quote:

Originally Posted by powercat_ras

Down in the center bottom of the junction box you posted a photo of, is a circuit breaker. Look for a button on one side of it you can push in to reset it , if it has tripped.

That might be your issue.

Powercat, you hit it right on the nail. I didn't clearly read your post and thought you were referring to perhaps a button on the converter. But there is a button on the breaker in the junction box. After talking to my local RV shop they showed me that there were two types one with a manual reset and one that you replace if broken. Then it dawned on me about the comment from Powercat and sure enough when I got home I found it, reset and all is good.

What a relief it wasn't anything more (hopefully). Not sure what may have tripped it, but it was at a Lazy Days service repair center for two months so no telling.

Thanks for all the help!

Morich · 11-21-2018, 10:53 AM

It could be some form of that but a terrible place to put it, so perhaps not. Trailers seems to be less supported in the way of drawings so we may need to guess a bit more! Is the heavy black cord going right, the shore power cord?
I normally think of junction boxes as being just a place to join wires, not to place things and finding 12VDC in the box with the shore power, would seem to break a few rules I use but the three yellows and one yellow lower may simply be an insulated lug/ or bolt used to tie various wires together and may not be connected to each other. It may need some pulling the red,yellow, black and blue wires back to get a better look.

Good deal, I type too slow!

Fasttimes · 11-21-2018, 11:18 AM

The heavy black cord coming in from the right is the RV - Car plug. The wires coming from upper left are from the converter side of things. The nest of wires is mostly the connections from the RV/Car plug to trailer lines. Lines lower right are from 12v battery side of things. Smack in the middle joining the systems is the breaker with two power posts.

BobC · 11-21-2018, 11:50 AM

I don't know if you read my post or not but it's probably an auto resettable breaker so it probably won't have a reset button. Read my post (#12) for more info.

Hopefully it's just failed and replacement will fix it. If the new one trips, you're pretty much back to square 1.

Fasttimes · 11-21-2018, 12:02 PM

Bob, it is a manual reset. I found it at the bottom of the breaker, size of the tip of a toothpick. Once reset all is well.

BobC · 11-21-2018, 12:25 PM

Great, I'm glad this worked out. You might want to put a label on the box cover in case you forget or, at least to help out a future owner.

1953m38a1 · 11-26-2018, 09:01 AM

Had similar issue with my coach(2008 Itasca 38T, Suncruiser). DW had ,in a shared preparation to move, tried to pull in the canopy, via the step area switch panel ,hit the auxiliary switch instead, of course it didn't move the canopy till she hit the right one,.BUT did not switch the aux 12V power back on!,,,what the ...no power, lights, fridge etc. Lots of head scratching to the ultimate discovery!
Always check the simplest fixes, "don't rewire the unit , to fix a burnt out lite!!

BobC · 11-26-2018, 09:43 AM

Ocaam's Razor (paraphrased) - The simplest solution is most likely the correct solution.

or, as Doctors are taught - "When you hear hoofbeats, think of horses not zebras"