From the "for what it is worth" file.
1) Put the firewall grommet in hot water (140-150 was what mine read)to soften it up a bit. Add a bit of Palmolive dish washing soap.
2) From inside the truck, push the dash harness wire connector (socket) though the firewall hole into engine compartment.
3) For leverage, I climbed into the engine compartment, straddled the engine with a foot on each side of the frame, and sat on the valve cover. I recommend removing the oil filler cap. Note: I tried leaning over the radiator and on my side from the fender and just could not push force and leverage.
4) Take the grommet, position it, tapered end, toward the firewall. Push it completely over the dash harness socket onto the wiring.
5) Push the grommet into the firewall hole and use a finger to to push all the way around and outward to make sure the firewall sheet metal is fully seated within the groove of the grommet.
5) Plug the engine harness (plug) into the dash harness (socket). This gives you something substantial to hold onto.
6) Angle the dash socket’s lip into the grommet’s internal groove on the bottom, backside (the area you cannot see from your vantage point), leaving the top forward portion visible. While holding the complete wiring harness connection firmly with the right hand and using the left to hold the right hand and twist, push the assembly into the grommet while simultaneously twisting it clockwise like you were threading it in. This will more than likely require a full 360 turn with constant pressure, but the wiring will take a single turn no problem. You know it is in completely and correctly in if you can turn it back counter-clockwise without it popping out. I actually felt it when it slipped into place in the grommet when I turned it backward
I tried to put the grommet into the firewall with the socket inserted into the grommet first and no luck. Note, this takes no prying or modification of the firewall hole or grommet.
Sorry no pictures but dang sure not taking it to do it again for staged photos.
Leadbelly
