7 way plug inside 72 ambassador

[Ryocomjr]

Hopefully I'm asking in the right area. I've searched and unless I'm not saying it right I'm not coming up with much. We have a 72 ambassador 29' and the brakes do not work. Originally when we got it they would lock up with just a 7 pin plug with no controller. I unhooked the white wire from the inside of the A/S I now have a new truck with controller and can't for the life of me remember where the white wire goes. Can anyone help?

[ijustlee]

On the trailer back then I think white was ground and yellow was brakes. It seems that you always need to set up your truck and trailer to match each other. There are a few standard color codes to chose from and your truck may be wired to one that is common for travel trailers but you will need to match wire to function for your trailer the first time.

[garry]

All the info needed to connect.

https://www.etrailer.com/faq-wiring.aspx

[Tom Nugler]

This is from the '72 service manual.
Hope it helps.

Tom

[alantbird]

I had 10 vintage airstreams in about 10 years and every single one was wired wrong so you just got to have trial and error and blue is usually the color for breaksome

[Ryocomjr]

Thank you guys for the replies. I guess I'll be out with a tester and trial and error