Seems like I remember finding a thread about it but can’t find it now. I’m in the process of doing e fuel and fixing up some of the wiring in the valley. I think that’s the old fuel heater plug that it’s tied in with. Thanks

 

I am interested as well. I bought a wiring harness and seen that and figured it had been modified. Then I seen it in my truck too and was even more confused.

 

Is it just a plug cap?

 

No it’s like a relay. Filled with a clear epoxy. Four wires go into the plug. Seems like maybe it was something that was only on the earlier models. This is a 95.

 

Mines a 97 and has, it the truck I got the harness from was a 96