Visit our Popular Forums

jrk247 · 07-10-2006, 06:31 PM

Hello All.
I got the new (to me) '77 31' Sovereign home last week. Spent all weekend cleaning and repairing what I could when all of the sudden all the 12v power stopped. So I got out the handy tester and discovered the univolt was putting out no power, it was plugged in and humming. I read on here that it's probably bad so I ordered an intelli-power. Anyway, it was getting dark out and I really needed the lights so that I could see what I was doing, so I hooked up the battery (fully charged) and got nothing. I poked around with the tester a little more and discovered that there wasn't any connection being made between the four spots where the negatives connect and the negative on the battery. The fuses weren't blown. The only way that I could get the power to work is by connecting the negative from the trailer to the battery directly. I hooked the univolt back up the same way to see if it would work and didn't get anything. I've attached a picture of the area. Any ideas on what's wrong here before I get the new unit hooked up?

john hd · 07-10-2006, 07:45 PM

you will find a fuse on the negative lead.

they are in various places on different trailers. look for it just below the univolt. it should be on a fiber block all by itself. it is a large glass fuse.

follow the large black lead and you will find it!

john

jrk247 · 07-10-2006, 08:51 PM

Thanks for the reply, there aren't any other fuses on any of the main wires except for the ones on the fuse panel. They aren't there in the picture, but they were plugged in and are good when I had the problem, the negative ones are on the top left. The univolt was wired diretly to the panel. The negative from the univolt connected to the bottom left of the 4 terminal area, and the positive was connected to the bottom of the battery fuse (not in the picture). There are also no other fuses between the fuse panel and the battery.

Excella CM · 07-10-2006, 10:17 PM

It looks as if the item in the top center may be a circuitbreaker.

jrk247 · 07-11-2006, 06:07 AM

The item in the top center is where the 12v connection from the hitch connects to the electric jack and then back to the distribution panel. There doesn't seem to be anything wrong with that. I think my issue is with that large flat square thing where the ammeter hooks up that is in the bottom center of the picture, I'm just not sure what the problem would be. Everything seems to be touching but nothing gets through.

kl8ton · 07-11-2006, 09:01 AM

I had the same problem....I just installed a WFCO converter from bestconverter.com and everything is well. I did have a 50A fuse on the negative battery wire that was mounted between the univolt and the battery.

dwightdi · 07-11-2006, 10:08 AM

Sounds like time for some ohmmeter checks on all the lines and connections. Also check from negative to trailer frame.

AYRSTRM2 · 07-11-2006, 10:59 AM

do you have a wiring schematic of your coach? That would help, they are in the users manual.

jrk247 · 07-11-2006, 02:14 PM

Quote:

Originally Posted by dwightdi

Sounds like time for some ohmmeter checks on all the lines and connections. Also check from negative to trailer frame.

What would this accomplish?

I do have the wiring diagram from the owners manual, but it is not helpful at all, it just says what colored circuit the fuses goes to, which doesn't tell me much.

crowbar68 · 07-12-2006, 02:53 AM

definetly need to meter everything out. sounds like the negative is open somewere between battery and univolt or univolt to fuses. if i'm not mistaken there looks like you have a couple fuses missing in the pic. i would even check the univolt itself to see if your getting 12v out. i would start w/ neg. to frame as mentioned.

crowbar

Over59 · 07-12-2006, 05:37 AM

Quote:

Originally Posted by jrk247

What would this accomplish?

I do have the wiring diagram from the owners manual, but it is not helpful at all, it just says what colored circuit the fuses goes to, which doesn't tell me much.

It would enable you to determine where the circuit is open. I assume you cleaned everything up.

herrgirdner · 07-12-2006, 09:19 AM

Quote: got the new (to me) '77 31' Sovereign home last week. Spent all weekend cleaning and repairing what I could when all of the sudden all the 12v power stopped. sounds like the univolt crapped out. So I got out the handy tester and discovered the univolt was putting out no power, it was plugged in and humming. I read on here that it's probably bad so I ordered an intelli-power. good so far. Anyway, it was getting dark out and I really needed the lights so that I could see what I was doing, so I hooked up the battery (fully charged) and got nothing. I poked around with the tester a little more and discovered that there wasn't any connection being made between the four spots where the negatives connect and the negative on the battery. The fuses weren't blown. The only way that I could get the power to work is by connecting the negative from the trailer to the battery directly. I hooked the univolt back up the same way to see if it would work and didn't get anything. confirms that the univolt is bad. I've attached a picture of the area. Any ideas on what's wrong here before I get the new unit hooked up?

from your description and the picture, i would guess that the PO had disconnected the battery from the univolt by removing the fuses from that fuse block in the lefthand side of the picture. your coach was then running on univolt power, and when it failed, the battery was not in the picture. if that's the case, a voltmeter reading across the terminals of the fuse block would probably be about 12 volts, if you have one light turned on to complete the circuit. (guessing that the battery side of the fuse block is connected to the negative terminal of the battery.) well, that's my guess as to what happened.
good luck.
and
regards

jrk247 · 07-12-2006, 04:51 PM

Ok, when I take the ohm meter to the circuits I get no reading...meaning there are no shorts right? When I take the ohm meter from the 12v negative to the frame I get a reading...which I should correct? I've attached a marked up picture of the way the wiring was done before I disconnected them and attached the 12v negative from the circuits directly to the negative for the battery. As I previously mentioned the fuse was installed and is good. When I connect the ohm meter to the four incoming negatives to the fuse to the battery I get nothing. When I take a reading across that flat plate I don't get anything either. So would removing that plate and replacing it fix the problem...i'm no me/ee, but I don't think that metal can just stop conducting electricity right? I guess that that area just needs rebuilt to work?

Thanks

overlander63 · 07-12-2006, 05:03 PM

Maybe. Is that a 12v charge line from the tow vehicle hooked to the three ground wires (univolt, chassis, and battery)? The charge line is positive as well, if that is what I am seeing.

brad50 · 07-12-2006, 05:28 PM

where are the wires going to the amp meter. if the amp meter is disconnected there is no circuit.

jrk247 · 07-12-2006, 06:50 PM

Quote:

Originally Posted by overlander63

Maybe. Is that a 12v charge line from the tow vehicle hooked to the three ground wires (univolt, chassis, and battery)? The charge line is positive as well, if that is what I am seeing.

I mislabeled it, it is the 12v negative from the truck.

jrk247 · 07-12-2006, 06:52 PM

Quote:

Originally Posted by brad50

where are the wires going to the amp meter. if the amp meter is disconnected there is no circuit.

I unhooked those wires when I was trying to figure out what was wrong. So they were hooked up when the problem started, just not during picture taking. The fuses in the amp meter wires are good, as well as the fuse on the control panel.

overlander63 · 07-12-2006, 07:05 PM

Quote:

Originally Posted by jrk247

I unhooked those wires when I was trying to figure out what was wrong. So they were hooked up when the problem started, just not during picture taking. The fuses in the amp meter wires are good, as well as the fuse on the control panel.

If and when you get this sorted out, you may want to consider a voltmeter instead of the ammeter. The voltmeter can tell you just as much as the ammeter, without the possibility of a short circuit in the gauge causing a meltdown, as the entire load will no longer have to pass through the gauge to show what is going on.

jrk247 · 07-12-2006, 07:33 PM

Quote:

Originally Posted by overlander63

If and when you get this sorted out, you may want to consider a voltmeter instead of the ammeter. The voltmeter can tell you just as much as the ammeter, without the possibility of a short circuit in the gauge causing a meltdown, as the entire load will no longer have to pass through the gauge to show what is going on.

So let me get this straight...on the negative end of things, when running off the battery the negative runs through the tiny wires to the ammeter and back before getting to the fuse for the battery? So if there is a problem with the ammeter that would explain why I can't run off battery power when everything is hooked up the way it was. How would I incorporate a voltmeter?

overlander63 · 07-12-2006, 07:39 PM

Quote:

Originally Posted by jrk247

So let me get this straight...on the negative end of things, when running off the battery the negative runs through the tiny wires to the ammeter and back before getting to the fuse for the battery? So if there is a problem with the ammeter that would explain why I can't run off battery power when everything is hooked up the way it was. How would I incorporate a voltmeter?

Yes, all loads go theough the ammeter. And the voltmeter is simple. Hook up 12v+ to one lead of the voltmeter, and ground the other lead. Voltage is shown, and can have a fuse to protect further against shorts in the line. The fuse can be as little as a couple of amps.