Rewiring Trailer Umbilical Plug

[DPeakMD]

My old receptacle at the front of trailer for the umbilical to the tow vehicle was shot. It was the original 1972, made out of plastic and the environmental exposure had taken it's toll over the years. The spring-loaded cover came apart and there was a risk of the plug sliding out just enough to lose connections to trailer brakes and lighting...not good.

I'll document my replacement story below:

1. The original was a "Signal Stat 3102". I could not find a direct replacement anywhere.

2. The all metal Pollak SAEJ560 looks very similar in design--but--it's deeper and will not make contact with the old plastic signal stat plug!

3. I liked the look of the Pollak. It's metal, it's silver-colored and it looks very rugged! My old Signal Stat plug was needing replacement anyway, so I bought the matching plug to go with this.

Below is a picture of the new Pollak next to the old Signal Stat

[DPeakMD]

OK-

That's the front of the receptacles, now for the back(inside the trailer). There are a few different types of connections to the Pollak receptacles: One is a terminal connection, one is a spade connector and another is meant for some type of pre-assembled wiring package used for semi-trailers.

The original Signal Stat used spade lug connectors. The only Pollaks I could find in stock were the terminal type--i.e., strip the wires, stick them in a hole and screw down the screw to hold them in. I wanted to get the project done before a trip...so I had to modify the spade connectors to fit into the holes. Folding the spade connector on itself lengthwise is a quick, if somewhat un-elegant, way to do this!

Here's a picture of the back of the old receptacle. The new one fits right into the old hole and is slightly longer, but the screws actually match up!

I'll post a picture of the final assembly as soon as I can locate it!

[jdleezer]

Replacing the receptacle is a project on my never ending list
(mine looks just as bad), so I'm really interested in your final assembly post. By the way, where did you get the all metal Pollak receptacle? Thanks...

[Happycampers]

I had the same thing on our 76 and like you wanted to keep the metal connection on the trailer. The plastic cord to the truck wouldn't fit smoothly into the metal, worked all day trying to get it to work and finely went to everything plastic and what was a 8 to 10 hour job should have been done in 1 to 2 hours. So what I would suggest is change everything to plastic and you will be happy you did. Marvin

[DPeakMD]

Here it is!

The trick must be to make it all metal, or all plastic--mixing the two styles does not seem to work very well. You'll notice on the profile that the metal receptacle is slanted and sticks out slightly further making the contacts too far inside to be reached by the original plastic plug which also has the little finger grip on the bottom to help pull it out.

I'm impressed by the holding power of the metal unit. The latch is strong and the whole thing is very solid. It will also survive the environmental exposure better than the plastic over the years. Unfortunately, my trailer lives outside!

Re-doing the connections on the inside was the hardest part. It's nice on the '72 because the plug is front and center and easy to get to behind the couch. I'm a little worried about how to get to the one our new '78 which sits off to the road-side. I haven't investigated it yet. That's a new project!

-Dallas