Reply
 
Thread Tools Search this Thread Display Modes
 
Old 05-09-2003, 02:03 PM   #1
1 Rivet Member
 
Join Date: May 2003
Posts: 13
No 12v Power

I'm working in my 1978 23' Safari, hooked up to my Suburban with the power cord, lights on inside trailer on 12V power, then sudden total darkness, no lights or anything else needing 12V. I then hooked up to 120V AC housepower and everything works fine, just no 12V at all. The fuses all appear to be OK, none look blown.
However, it appears the batteries are not being charged as my voltmeter is reading only 11.6 volts even when plugged into 120V this reading was made at the 12V fuse panel by holding meter leads on the ends of the 50 Amp fuse for each of the two batts.
So my question is what do I do to isolate the problem, what is anyone's opinion of what the problem might be, and if it's the charger/converter (is this the univolt?) gone bad, is it fixable and if not , how much do they cost. I just bought this trailer and really want to be able to use it, but I want the 12V power system and everything else to function properly. THANKS IN ADVANCE TO ANY RESPONDERS. I'm a new member and this is my first post. I must say I'm impressed by what I see here.
W. C. (Court) DeLorme, Azle, Tx.
__________________

__________________
wcdelorme is offline   Reply With Quote
Old 05-09-2003, 02:19 PM   #2
3 Rivet Member
 
1962 19' Globetrotter
2001 31' Excella
Join Date: Aug 2002
Posts: 242
Images: 3
WC,

People here will know much more about this subject than I do, but I did have the same problem. When the Univolt is working, you should hear a buzz. But mine was buzzing and still not converting the ac to dc. I didn't spend much time trying to isolate it since I wanted to get rid of the buzz anyway, I just replaced the Univolt and everying worked great. It's a very easy swap out of the old unit to a new one.

I replaced the Univolt with the Inteli-Power PD9160. Contact Randy at klevenent@sw.rr.com for a great price and service if you decide to replace.

Craig
__________________

__________________
Craig is offline   Reply With Quote
Old 05-09-2003, 03:12 PM   #3
1 Rivet Member
 
Join Date: May 2003
Posts: 13
no 12v power

Thanks, Craig
Is this an expensive device to buy? Also, I read someone's post on another site and he said "This is a major project to install as far as Airstream electrical projects go, but worth it" I'm hoping that your answer is closer to reality when you state that it's an easy switch to make. So, is it your opinion that my univolt has failed causing the blackout? I'll check with your source for the intellivolt and again, thanks. W.C.
__________________
wcdelorme is offline   Reply With Quote
Old 05-09-2003, 03:31 PM   #4
3 Rivet Member
 
1962 19' Globetrotter
2001 31' Excella
Join Date: Aug 2002
Posts: 242
Images: 3
I can't say that your Univolt is definitely the cause, but I know it was the source of my problem. If your fuses are fine, the Univolt is plugged in, and you have AC connected to the trailer and still no DC, it very well could be the univolt.

As far as the "project" is concerned, on a 78 the switchover is easy. Check out how your univolt is connected. It should just plug in to a 120v outlet and it will have three wires running to the fuse box. Just unplug and loosen the wires to the fuse box and you have the Univolt removed. Reverse the above to put a new converter in.
__________________
Craig is offline   Reply With Quote
Old 05-09-2003, 03:41 PM   #5
1 Rivet Member
 
Join Date: May 2003
Posts: 13
no 12v power

Craig, how nice to have someone respond so quickly and with the experience of having done it. I'd say from your description that a changeover couldn't be much simpler than that. I sent an email to your source for a quote on the unit with a charge wizard. I'll let you know what I find out. When I get home I'm going to pull all the 12v fuses and check with my voltmeter and look carefully for any loose wires. If all checks out, then I'll be replacing the old univolt for sure. Thanks, W.C.
__________________
wcdelorme is offline   Reply With Quote
Old 05-09-2003, 03:46 PM   #6
Retired Moderator
 
john hd's Avatar
 
1992 29' Excella
madison , Wisconsin
Join Date: Aug 2002
Posts: 4,644
Images: 40
fuses and stuff

wc

welcome to the forum.

you said the fuses looked fine, looks can be decieving.

check them with an ohmmeter, look for a zero ohm reading from one end of the fuse to the other(removed from unit).

is the univolt humming/buzzing?

also, the ground wire is fused.

you might try charging the batteries seperate from the trailer. checking to make sure they take and hold a charge.

i have some internal pics of a 70's univolt if that helps. and part numbers.

john
__________________
john hd is offline   Reply With Quote
Old 05-09-2003, 04:48 PM   #7
Moderator Emeritus
 
overlander64's Avatar
 
1964 26' Overlander
1978 Argosy Minuet 6.0 Metre
Anna , Illinois
Join Date: Sep 2002
Posts: 5,396
Images: 183
Send a message via Yahoo to overlander64
No 12v Power

Greetings WC!

Welcome to the forum and the world of Vintage Airstreaming.

I wouldn't condemn the Univolt too quickly - - it may very well be the problem, but there are some other potential culprits as well:

1. Locate the Univolt and determine that it is either hardwired into your electrical system or plugged into an outlet (the precise method used varied by year - - my '64 Overlander was hardwired and my '78 Argosy Minuet is connected to an outlet.

2. Verify that the Univolt is receiving power, and if it isn't
A.) Check the main circuit breaker box to see if all circuit breakers are functional.
B.) Check for a cut-off switch (these are often located close to one of the sleeping areas or on a panel adjacent to the Univolt's location).

Also, you mention having 12-volt lights - - possibly via the connection to your tow vehicle - - then suddenly nothing. Have you checked the cables running to the (coach) battery to see if there is an in-line fuse that may have blown for some reason disabling the 12-volt electrical system. Also, there should be a fuse or circuit breaker in the charge line from the tow vehicle and it may have blown resulting in no 12-volt. When you mention a reading of 11+ volts from the battery, it would seem that there should be at least some glow from the lights even if the Univolt is gone. When the Univolt in my '78 Minuet gave up, the 12-volt lights worked so long as the trailer had a charged battery or was hooked up to the tow vehicle.

If you find that the Univolt is getting power yet there is no hum, it very likely may be the cause of your problem. The Univolt in my Minuet ceased functioning last fall, and my local Airstream dealer replaced it with the power converter that Airstream is currently using in production coaches.

You mention concern about the difficulty of replacing the Univolt. I didn't replace mine due to lack of time. The greatest potential problem is usually where the 12-volt fuse panel is located - - if it is separate from the Univolt then the replacement is rather straight-forward; if, however, it is part of the Univolt it may be necessary to wire in a 12-volt sub-panel depending upon the new converter that is chosen. I am not certain, but have the impression that the Univolts with built-in fuse panels predated '78.

Good luck with locating your 12-volt problem.

Kevin
__________________
Kevin D. Allen
WBCCI (Lifetime Member)/VAC/Free Wheelers #6359
AIR #827
1964 Overlander International/1999 GMC K2500 Suburban (7400 VORTEC/4.11 Differentials)
1978 Argosy Minuet 6.0 Metre/1975 Cadillac Eldorado Convertible (8.2 Liter V8/2.70 Final Drive)
overlander64 is offline   Reply With Quote
Old 05-09-2003, 05:19 PM   #8
1 Rivet Member
 
Join Date: May 2003
Posts: 13
no 12v power

Hi John, I'll ck for fuse in univolt ground wire. Also, I'll look for zero ohm reading end to end on all fuses and listen to see if univolt is humming. I don't recall if it was humming or not. If fuses are all good and univolt isn't humming when plugged in does that mean the univolt is dead? As I said in my original post, the batteries are not being charged even when plugged into 120V ac. Thanks for your input. W.C.
__________________
wcdelorme is offline   Reply With Quote
Old 05-09-2003, 05:26 PM   #9
1 Rivet Member
 
Join Date: May 2003
Posts: 13
no 12v power

Hi Kevin, thanks for your input. All you guys have given me some great ideas for checking stuff. I'll keep everyone informed of what I find. I'll spend time this weekend and hopefully isolate the problem. Again, thanks to all. W.C.
__________________
wcdelorme is offline   Reply With Quote
Old 05-09-2003, 06:35 PM   #10
Retired Moderator
 
john hd's Avatar
 
1992 29' Excella
madison , Wisconsin
Join Date: Aug 2002
Posts: 4,644
Images: 40
dumb line man

Quote:
Originally posted by wcdelorme
Hi John, I'll ck for fuse in univolt ground wire. Also, I'll look for zero ohm reading end to end on all fuses and listen to see if univolt is humming. I don't recall if it was humming or not. If fuses are all good and univolt isn't humming when plugged in does that mean the univolt is dead? As I said in my original post, the batteries are not being charged even when plugged into 120V ac. Thanks for your input. W.C.
let me correct my self, the negative is fused. large black wire.

the ground is not fused.

it is my lineman training in ac circuits that refers to ground as neutral.

please forgive my error!

john
__________________
john hd is offline   Reply With Quote
Old 05-09-2003, 08:28 PM   #11
Rivet Master
 
garry's Avatar
 
1969 31' Sovereign
Broken Arrow , Oklahoma
Join Date: Jan 2003
Posts: 1,362
Images: 7
The univolt is known for overcharging and running batteries dry so many people put in a cut out switch to prevent this so when connected to 120 VAC the battery is in fact disconnected. Later model AS came with a cutout switch but I don't know when.
. The problem you stated that power droped out from the Surburan sounds more like a bad connection at the connector.

Garry
__________________
garry is offline   Reply With Quote
Old 05-10-2003, 05:42 AM   #12
3 Rivet Member
 
1993 29' Excella
Jonesboro , Louisiana
Join Date: Apr 2002
Posts: 125
Don't condem the univolt too quickly. If the tow vehicle is plugged in and running, you don't need the univolt to charge the batteries. Sounds like an open circuit between the 12 volt panel and the batteries-could be a bad battery as well. Check this angle first but be sure the Suburban is running as the 12 volt suppy is turned off with the key in later models. Good luck.
__________________
James Schmidt
29 ft Excello 1000
97 Expedition/Hensley Hitch/
McKesh mirrors
James Schmidt is offline   Reply With Quote
Old 05-10-2003, 08:46 AM   #13
1 Rivet Member
 
Join Date: May 2003
Posts: 13
no 12v power

Thanks Gary and James. The suburban was running and all was well when it just suddenly went black. Since then, no 12v power at all whether hooked up to vehicle or not. Tried putting my 20amp battery charger on battery #1 and still no power. All works fine if plugged into 120v ac. I'll ck all the suggestions offered by everyone this weekend and post results. Again, thanks a million for all the input. W.C.
__________________
wcdelorme is offline   Reply With Quote
Old 05-11-2003, 10:53 AM   #14
1 Rivet Member
 
Join Date: May 2003
Posts: 13
no 12v power

Problem solved. Thanks to all who offered suggestions. I used them all. Here's the deal. I checked voltage the univolt (which I found had been replaced with something called a "Magnetec") but is probably about the same thing. I found 120v AC there and it was humming. Found two 50 amp fuses that looked fine but were bad, found the positive wire from the Magnetec was very loose, found one of the two batteries not connected at all at the pos/neg connector inside the battery compartment, found both batteries had corroded and loose cables (I just lifted them off the posts by hand without even having to loosen them). Checked voltage output at batteries and found both putting out under 11 volts. Corrected all above problems and plugged back into housepower for about 4 hours. Found Magnetec putting out 13.62 volts into the batteries and they were warm to the touch, obviously being charged now. Disconnected housepower and turned on interior lights. Voila!!
There was light, the radio worked, the pump pumped, the fans fanned, It appears all is well.
So again, thanks to everyone. This forum is tops. Now if someone can tell me where to get a new end piece for the cab over the galley I be all squared away. It's the triangular plastic end cap that has a brown upholstered trim piece in the center. Hope everyone had a great Mothers' Day weekend.
__________________

__________________
wcdelorme is offline   Reply With Quote
Reply

Tags
12v


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
12V System....Sudden Death! Help, please Alan and Mardel Electrical - Systems, Generators, Batteries & Solar 6 12-13-2003 12:04 PM
12V power loss sladew Electrical - Systems, Generators, Batteries & Solar 2 08-05-2003 05:47 PM
Newbie needs Classic 28' power management info Dave Jenkins Electrical - Systems, Generators, Batteries & Solar 3 07-24-2003 06:11 PM
B190 Coach power problem Luckydog Sprinter and B-van Forum 21 11-12-2002 01:59 PM
12V question uwe Electrical - Systems, Generators, Batteries & Solar 16 09-05-2002 02:14 PM


Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 08:02 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.