Engine Block Heater Plug Mount

I wanted to install an EBH, but didn't want the cord hanging out front, so I devised the following to use my left fog light blank. I actually purchased a spare set from Spidey (Thanks!!!) in case I didn't get it right the first time. This will be a bit of a long thread, but hopefully will help anyone looking to do the same. This will also be several parts as I find the time to actually do the install.

1. Buy a boat charger plug, some 12/14 gauge extension cable, a female plug, and optionally some of the other items pictured below. I used a Marinco 150BBI that I got off eBay).


2. Tape both sides of the fog light blank to prevent tearout and hard-to-remove melting plastic from sticking to the blank.


3. Use the retaining nut to trace your cut line around the previously taped inside of the fog light blank. You'll want drill from the inside to make it easier to press on the plastic without it flexing and making a mess of your hole.


4. Using a 1-3/4 inch hole saw drill bit, drill a hole from the inside of the fog light blank. The size hole is actually 1-7/8, but these are an uncommon size for hole saw sets. It's easy enough to file out to fit anyway.





5. File, check, file, check... until you get the fit nice and tight.










Note the ground plug/wire is at the top. This is a standard electrician approach, and supports the drain hole being at the bottom in case water does find its way in.

6. Carefully trim the excess melted plastic away to allow for a better final fit



7. Use a nail and your fingers as a gauge to measure the required length of wire for the receptacle.


8. Strip and trim the extension cord cable to the proper length indicated by the "fingers gripping nail" technique described above. I use a 2-step process to get just the right length. First, trim to the length indicated by the nail, cut the fiberglass flush with the external insulation and strip the wires. Second, trim an additional 1/2 inch from the external insulation (allows bending length for the wires to go into the receptacle), and trim the fiberglass again to flush.








9. Insert the wires into the appropriate color holes and tighten them.



10. (Optional) Color match your fog light blanks to the boat receptacle. Use mineral spirits to clean and prep the plastic for paint. I used Duplicolor Trim Black, and it matches the grilles very well in addition to matching the Marinco 150BBI. I also used a heat gun at low setting to hasten the drying time and slightly flatten the paint color.






11. Slide the boot onto the extension cord from the unprepared end of the extension cord (this will be a bit challenging since it's a very tight fit).



12. Apply silicon caulking on the inside of the mounting hole for the receptacle and tighten down the retaining screw. The silicon keeps the retaining screw on as well as preventing water from easily getting inside. Apply a bit more silicon around the boot mount and slide the boot mount on back of the plug.



More in the next couple weeks after I install the EBH and figure out the wire routing and mounting.

 

I was a bit concerned about the cap wearing out over time when I was debating between the different receptacles, and appreciate you validating my concern . I figure I'll give it that year or so, and look to a spring-loaded cap when it does happen if I can't figure out a way to fix it (soft adhesive or similar).

I was still debating about using the 3 screws, and plan to wait to find out how well/bad it works once I mount it before deciding. I'm actually more worried about having enough rigidity with the fog light blank or bumper than the plug, but I'll have to wait and see.

Thanks again for the inputs and lessons -- I'm sure they'll come in handy.

 

I finally finished it this weekend, and it turned out pretty good I think. I didn't take pics of the install into the car since it's well covered in other threads with fog light installations. The only note I'll add to that is using waterproof electrical tape around the EBH plug to receptacle plug connection, as well as tie-strapping the wires to wire harnesses -- very easy to figure out and do.

Anyway, here are some pics: