Originally Posted by pfay
We just bought a 1969 27’ Overlander and need help with the wiring from truck to trailer so we can bring her home. There are bear wires sticking out of the hitch and I need to know what kind of plug I should buy and the best way to determine how to wire it correctly....
Since you only have bare wires showing now, do a bit more exploring and determine if you have a connector and harness where the wires enter the trailer body.....
You will most certainly need a new male connector for your TV - a new connector should show the existing wiring diagram on your TV pins....
If you do purchase an entire new harness, utilize the appropriate connector for the trailer end and connect the bare wires from the trailer to the harness in such a manner as the new connector will fit a "standard" modern hookup - that way you will be ready for just about any other trailer you may wish to tow with your TV - and also make your "vintage" AS towable with any TV with a "standard" pin connection.
Now...be cognizant of the fact that Airstream used their own "unique" color codes, and the color codes of a new connector will PROBABLY NOT match the color codes given previously and below.
Plan on spending at least 4 hours of checking for correct wires and wiring the harness if you have never done it before. I would really recommend bringing a portable 12 volt
battery and a cheap volt/ohm meter to actually check the function of each wire...when I picked up the Sovereign
in Ohio the PO had overtightened the wire pull-out preventer and actually shorted three of the wires internally - I literally burnt up two 20 gauge jumpers trying to figure out what was going on - I am sure glad it was the jumpers that failed (sort of a fuse) instead of the harness wiring or the trailer wiring.
I have attached a jpg of the wiring diagram from the owners manual of the '78 below - note that the color and rotation are the same as the previous post pictoral, but a different type of connector is indicated.
If you are not comfortable working on the light and brake system please find someone who has some knowledge of it...it is not diffficult, but, as others have stated, you MUST have lights on the trailer, even for a short haul.
I would certainly have the brake controller installed professionaly if there is any doubt on your part if you can do it quickly and easily...most any trailer sales place and, I think most of the larger U-Haul type places do the installations....you well may already have the wiring already installed in your TV - requiring only (a) spade connector(s) to get the signal back to the 7-pin.
In my opinion, the brakes get much less of a workout on a 4 lane as opposed to 2 lanes - usually fewer starts and stops - your call on that, though.
ALWAYS err on the side of caution - you're only 75 miles away from the trailer - if you run into problems - or out of daylight - just come back to retrieve it another day - it will still be there.
Don't forget to check the dates on the tires - do a search here for "tire date code" or similar - if you are going to have to change out the tires you might as well do it before you tow it home and not take a chance on throwing a tread gator into your new aluminum - you can repack the bearings and check the brakes at the same time.