The original wiring harness did not have a "4 way unit" so it's difficult to help you find a diagram without further information.
The original wiring diagram can be found in your 1954 Chevy truck shop manual. If you don't have one then look here.

http://chevy.oldcarmanualproject.com/shop/1954truck/54ctsm1202.html.

more info here.
http://chevy.oldcarmanualproject.com/electrical/wiring/pdf/54truckwiring.pdf

You can also look in tech tips for some helpful information "How do I wire my turn signals?".

BTW, the forum hasn't heard back from you on reinstalling your steering column. I guess all worked okay?

Last edited by buoymaker; 06/16/2021 4:59 PM.
"Adding CFM to a truck will only help at engine speeds you don't want to use."
"I found there was nothing to gain beyond 400 CFM."