As a temporary measure (until I find a route for 10 gauge wire from the battery thru the firewall) I want to use a fuse tap (e.g. https://www.napaonline.com/en/p/NW_785171 ) to power a ham radio with a maximum draw of 12 amps and a low duty cycle the way I use it.

In the passenger footwell fusebox fuse number 27 is a 30 amp micro2 fuse for the moon-roof that I don’t have on my ‘17 F-350 XL 6.2L. I can’t get the leads from my meter into the fusebox so I can’t determine if fuse 27 is indeed hot. Question 1 is, is that fuse (or fuses 25 or 26 (for window motors that I also don’t have)) hot?

Question 2 is can anyone recommend a good ground near the footwell fusebox?

thanks,,,

 

Get a tail light with a pigtail (like used for temporary trailer wiring)
Ground one lead and run the other to one side of the empty fuse socket and then the other.
See the light?

 

I'm not familiar with temporary taillights. Do they get their power and ground within the cab? If not then I'm presented with the same problem of getting my 10 gauge wire into the cab.

I also still don't know if I have power to my non-existent moon-roof.

thanks,,,

 

I just ran my Ham Radio power wire to a grommet under my drivers side carpet, It is the rubber grommet that the step wire goes through. Then up to my upfitter switches so I can turn the radio on and off with that switch.

 

The grommet on the driver side near the brake booster. there. Is a nipple you cut off to run wires through.

 

WB6ANP:

On my '11 F-250 I used a long grommet under the passenger's side floor "covering". I haven't yet pulled up the floor covering in the '17. Pulling plastic parts with breakable tabs gets me up-tight but I'll just have to do it.

I guess that if you knew about power to the non-existent moon-roof fuse you would have offered it.

thanks,,,

 

JonathanJr:

While looking for the grommet with the nipple I found another grommet I'd missed before. It is just below the windshield washer hose and one of the cables going thru it powers the hood light. The grommet even says "PUSH" on both the top and bottom. It was easy to remove but no amount of messing about with a fish tape helped me find where it went. This grommet has the advantage of accessibility to both sides so I know for sure that I won't be cutting into something that I'll regret.

If we are talking about the same grommet the nipple has a flat surface nearly ½ inch in diameter. There is what I think is a score mark about 1/8 inch back from the flat surface. Do you know if there is a membrane left to go thru? If not I’d rather drill and force-fit the wires.

thanks,,,

 

This is the one i went through. I pulled it into the cab and sniped it with scissors and poked through with a screw driver.

 

I think I'm catching on. What you pulled, snipped, and poked was an inner membrane on the cabin side of the firewall. Did I get that right? The steps are 1) cut the nipple on the score mark, 2) penetrate the inner membrane, and 3) push the wire thru. After I hear back from you I may still chose to drill thru the nipple.

Did you do anything to weatherproof the point where the wire enters the nipple?

I'll put to rest the utility of the grommet labeled "PUSH". Instead of using the fish tape I waited for dark and shined a light thru the open grommet. With the door weatherstripping removed I couldn't see anything. I also saw nothing in the footwell.

thanks,,,

 

ya once you cut it it is open except for the inner membrane. I haven't done any thing else for water proofing as the inner membrane is tight against the wires you can put a zip tie on the outer nipple to seal it.

 

JonathanJr:

I really appreciate your help. I had looked at that grommet before and just didn't understand what I was seeing.

A modest (I think the technical term is) glob of RTV will likely keep ice out of the grommet. Now I have some work to do this weekend!

Again,,, many thanks.

 

I'm a Ham too, N7CQV, and I've got a 2019 F250 on order. Please show some pictures after your rig's installation is complete. What are you doing for the antenna?

 

Ray:

I've got a hole in the roof with an NMO mount. I'm hardly active at all (APRS mostly) and in the front range of CO a gain antenna isn't important so I use a ¼λ antenna. On my ‘11 F-250 the flat thin sheet metal roof seemed flimsy and I didn’t want much wind load up there. On the ‘17 F-350 the aluminum seems to be about 1/10 inch thick and has stamped channels for stiffness so I may reconsider a gain antenna, if only for traveling.

If you drill a hole in the roof consider your reach: if you suddenly find yourself driving into a parking garage with restricted height you will want to reach the antenna easily.

n4lbl

 

I've always hated the idea of drilling holes in the roof. When I was actively running a 2 mtr rig, I used a magnetic mount and routed the RG around the door molding, but I was never very happy with it. I'm waiting to get my 2019 SuperDuty and then I'll decide what I want to do.

 

Mag mounts don't work too well on aluminum!