Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×
 


Reply
 
Thread Tools Search this Thread Display Modes
 
Old 05-25-2007, 02:00 AM   #1
Rivet Master
 
Lumatic's Avatar
 
1971 25' Tradewind
1993 34' Excella
Currently Looking...
Estancia , New Mexico
Join Date: Feb 2005
Posts: 7,742
Images: 16
Blog Entries: 1
'71 Tow vehicle/trailer 7 way connector wiring

Worked on my 7 way connector today and found some odd things. It looked to me like a PO was fiddling with it.
1. There were 2 red wires for a turn signal. should only be one I guess. Only one for the other turn signal. Disconnected one and it didn't seem to make any difference. Why? Did the factory or AS put in 2 lighter guage wires to make it the equivalent of a heavier wire, or could the other wire do something else?

2. When I went inside and took off the 7 way access cover I found the white ground wire I fiddled with for 15 minutes on the outside was not connected to anything. There was another heavy guage white wire from the wiring harness which is too short to reach the exterior 7 way plug. Could the loose wire be someones idea of a ground extension piece to connect the too short wire? Right now no ground wire is connected and the exterior lights seem to work fine. I am guessing because the system has redundant grounds and the TV ground and trailer ground are connected by the tow hitch contact anyway. I think connecting the white ground wires to the 7 way shouldn't hurt anything? (famous last words) I'm not sure but I suspect the PO had a problem blowing the small 40 amp fuses in the Univolt, but not sure why.

Anybody ever encounter a situation like this? I wonder if this was the factory or a PO's work around of a problem I am not aware of.

3. There is some kind of electronic device in the trailer wall near the 7 way. from the wiring schematic I figure it to be a 25 amp circuit breaker. Kind of a strange, inaccessable place to put one. Anything else it could be? Like secret alien spyware. I am not too far from one of the three purported Roswell alien crash sites you know.
__________________
Sail on silver girl. Sail on by. Your time has come to shine.
Lumatic is offline   Reply With Quote
Old 05-25-2007, 10:52 AM   #2
Rivet Master
 
Join Date: Dec 2002
Posts: 1,335
Images: 4
Quote:
Originally Posted by Marshall
There is some kind of electronic device in the trailer wall near the 7 way. from the wiring schematic I figure it to be a 25 amp circuit breaker.
Marshall, that is probably an auto-resetting thermal circuit breaker. If there's excess current it gets hot and opens the circuit. Once the device cools down, it automatically re-makes the circuit. It's a little black rectangular gadget, about 4 cm by 2 cm, IIRC, and on my trailer it's screwd to the wall near the charger.
Nick.
__________________
Nick Crowhurst, Excella 25 1988, Dodge Ram 2500 Cummins Diesel. England in summer, USA in winter.
"The price of freedom is eternal maintenance."
nickcrowhurst is offline   Reply With Quote
Old 05-29-2007, 07:41 PM   #3
1 Rivet Member
 
1998 34' Limited
christiansburg , Virginia
Join Date: May 2007
Posts: 13
Marshall, the little red wire needs to go on top of the big white wire.Thats how it did on my 72 Overlander , the small red wire is a ground for the brakes.If igured this out the hard way. Hope this helps.

Dewayne
gretchen is offline   Reply With Quote
Old 09-23-2007, 09:16 PM   #4
TIG welder, 30 years expe
 
1973 25' Tradewind
Wilson , New York
Join Date: Sep 2006
Posts: 20
I just looked in the wall cover today for the first time on my '73 TW. The circuit breaker is permanently open, fried because I paid a guy who is supposed to know how to do this stuff, connect the brake control, etc. He has the main center post as a ground, and it is supposed to be 12V to the battery. No wonder the univolt died! ( Replaced with a charge wizard) No wonder I have been having trouble with getting a charge to the battery! I might get it all sorted out this year!
BMW Sid is offline   Reply With Quote
Old 09-24-2007, 04:40 AM   #5
Rivet Master
 
Ganglin's Avatar
 
1971 27' Overlander
Central , Ohio
Join Date: Jun 2006
Posts: 2,365
Images: 13
7 Way Systems

Round 2" diameter connector allows additional pin for auxiliary 12v power or backup lights.

7 way RV flat blade tow vehicle side.
7 way RV flat blade trailer side.
Ganglin is offline   Reply With Quote
Old 09-24-2007, 05:59 AM   #6
Rivet Master
 
87MH's Avatar
 
1978 31' Sovereign
Texas Airstream Harbor , Zavalla, in the Deep East Texas Piney Woods on Lake Sam Rayburn
Join Date: Jan 2003
Posts: 2,435
Images: 292
The way the Mother Ship did it - 1978 Model version!

Unfortunately, Airstream had their own convention.

Double click on the below images to enlarge.

Whenever you get a "new" old trailer it's always best to check out the functions with a cheap voltmeter and/or a fused circuit probe and battery.

Also included is a pic of the trailer fuse block showing the internal color codes and fusing of the trailer/towvehicle connection once the 7 way enters the trailer.

Other years may vary.
Attached Thumbnails
Click image for larger version

Name:	7way resized to 1200.jpg
Views:	1792
Size:	105.8 KB
ID:	45942   Click image for larger version

Name:	7way Fuses resized to 1600.jpg
Views:	518
Size:	394.7 KB
ID:	45943  

__________________
Dennis

"Suck it up, spend the bucks, do it right the first time."

WBCCI # 1113
AirForums #1737

Trailer '78 31' Sovereign

Living Large at an Airstream Park on the Largest Lake Totally Contained in Texas
Texas Airstream Harbor, Inc.
87MH is offline   Reply With Quote
Old 08-14-2010, 10:18 AM   #7
4 Rivet Member
 
Distantdrummer's Avatar
 
1975 31' Sovereign
Houston , Texas
Join Date: Nov 2003
Posts: 494
Marshall (Lumatic) which of your two trailers are you speaking of in this thread?
~edit~
I see now you mean the '71.

I am searching for that thermal circuit breaker on a 75, not found yet.
I wonder if they are always near the 7-way male (trailer side) access box?

BTW
Anyone know if electronic Contact Cleaner (aeresol) is harmful to the plastic sockets that the 7 ways are usually made of?
__________________
__________________________
____ d'drummer ____

...aahh..rumm..pu..tum..tummm...
Distantdrummer is offline   Reply With Quote
Old 08-14-2010, 01:01 PM   #8
Rivet Master
 
mello mike's Avatar
 
1958 26' Overlander
Mesa , Arizona
Join Date: Jul 2004
Posts: 1,742
Images: 53
Quote:
Originally Posted by Distantdrummer View Post
I am searching for that thermal circuit breaker on a 75, not found yet. I wonder if they are always near the 7-way male (trailer side) access box?
Yes, they are normally found attached to the front access cover for the 7-pin connector. My '72 didn't come with any thermal circuit breakers (don't know if they were removed by a PO or not). I ended up installing one for the 12v tow line.
__________________
1958 Overlander
2011 Wolf Creek 850N TC
2011 Ford F-250 Crewcab (6.2L), 3.73RE

WBCCI #5661/AIR #5661/TAC # AZ-6
4CU 1st VP

My '58 Overlander Restoration and Travel Blog:
https://mellomikesairstreams.blogspot.com/
mello mike is offline   Reply With Quote
Old 08-15-2010, 04:33 PM   #9
4 Rivet Member
 
Distantdrummer's Avatar
 
1975 31' Sovereign
Houston , Texas
Join Date: Nov 2003
Posts: 494
OK it looks to me that a circuit breaker in the 12volt-Tow-Line (pigtail, lifeline) unit could result in a bad situation. Got to figure the time it would overheat & open would be during towing on the road. So operator would be without stop lights, brakes, turn signals and every other trailer item.
Assuming the pigtails were constructed correctly with the right gauges of wires (three 14s, two 12s and two 10s)(if I remember Inland Andy's recipe correctly) then what would cause the circuit to over heat and throw (open).
I am also assuming that the operator does a walk-a-round before each tow and checks all lights. Not sure how one would check the brakes in a walk-a-round.
__________________
__________________________
____ d'drummer ____

...aahh..rumm..pu..tum..tummm...
Distantdrummer is offline   Reply With Quote
Old 08-15-2010, 05:14 PM   #10
Rivet Master
 
Splitrock's Avatar
 
Currently Looking...
Sioux Falls , South Dakota
Join Date: Jun 2010
Posts: 2,403
Blog Entries: 20
On my trailer there are 7 wires that come from the tow vehicle. One is a ground that goes right to the trailer 12 volt system as a ground and is tied to the body (as a ground). One is the right brake/signal light and is fused. One is the left turn/brake light and is fused. One is the tail/running lights and is fused. One is the back up lights, and is fused. One is the brakes and is not fused. One is the 12 volt line tied to the tow vehicle voltage regulator, used to charge the trailer battery, and is fused.

None depends on the other. If the 12 volt charging fuse blows, the battery just won't charge, but the brakes and all the trailer lights will work if they are properly wired and connected.
__________________
Click on the link to see a picture of the Sioux River falls near my home.
https://visitsiouxfalls.com/assets/i...uxfalls-og.jpg
Eastern South Dakota is very pretty with hills, rivers, and trees.
Splitrock is offline   Reply With Quote
Old 08-15-2010, 05:35 PM   #11
Rivet Master
 
Splitrock's Avatar
 
Currently Looking...
Sioux Falls , South Dakota
Join Date: Jun 2010
Posts: 2,403
Blog Entries: 20
To check my brakes, I just slide my brake controller while the tow vehicle is connected to the trailer and the rig is moving.
__________________
Click on the link to see a picture of the Sioux River falls near my home.
https://visitsiouxfalls.com/assets/i...uxfalls-og.jpg
Eastern South Dakota is very pretty with hills, rivers, and trees.
Splitrock is offline   Reply With Quote
Old 08-15-2010, 08:05 PM   #12
4 Rivet Member
 
Distantdrummer's Avatar
 
1975 31' Sovereign
Houston , Texas
Join Date: Nov 2003
Posts: 494
Splitrock it sounds like the thermal circuit breaker mentioned above is before any fuse panel and if I understand correctly it would knock out all the 12-volt in the trailer. If that is the case I don't understand it's relevance.
__________________
__________________________
____ d'drummer ____

...aahh..rumm..pu..tum..tummm...
Distantdrummer is offline   Reply With Quote
Old 08-15-2010, 08:19 PM   #13
Rivet Master
 
Splitrock's Avatar
 
Currently Looking...
Sioux Falls , South Dakota
Join Date: Jun 2010
Posts: 2,403
Blog Entries: 20
Quote:
Originally Posted by Distantdrummer View Post
Splitrock it sounds like the thermal circuit breaker mentioned above is before any fuse panel and if I understand correctly it would knock out all the 12-volt in the trailer. If that is the case I don't understand it's relevance.
My trailer has a fuse on the battery positive connection right above the battery box, which is below the kitchen range, curbside.

If I loose that fuse I'd lose interior 12 volt unless I'm on shore power. If I lose 12 volt in the trailer, my exterior lights and trailer brakes will all work if the trailer is attached to the tow vehicle. If I lose my battery, the break away switch won't work in a towing break away.

My trailer has two separate 12 volt electrical systems.

Gary
__________________
Click on the link to see a picture of the Sioux River falls near my home.
https://visitsiouxfalls.com/assets/i...uxfalls-og.jpg
Eastern South Dakota is very pretty with hills, rivers, and trees.
Splitrock is offline   Reply With Quote
Reply


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
1/2 Ton Tow Vehicles brianw Tow Vehicles 39 09-08-2011 06:44 PM
Help a girl find a tow vehicle star kitty Tow Vehicles 58 08-14-2011 07:51 PM
What to tow with what hankyknot Tow Vehicles 1 05-09-2011 02:32 PM
The ultimate tow vehicle! I found it! brad1 Tow Vehicles 8 03-21-2011 07:47 PM


Featured Campgrounds

Reviews provided by

Disclaimer:

This website is not affiliated with or endorsed by the Airstream, Inc. or any of its affiliates. Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.



All times are GMT -6. The time now is 04:28 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.