Topic: Help Please?: Identifying Mounting Holes in Trunk Floor Pan

[Angela]

I'm embarrassed to admit I cannot recall what the two circled holes are for.  Can anyone remind me what the two circled holes are used for? They appear to be partially (but not entirely) covered by the fuel tank mounting flange.

I believe the larger dia hole in the middle is for the fuel sending unit wire.

Also, is the small dia hole (indicated by the arrow) for some sort of grounding wire?

Thanks.

[Bob Gaines]

I'm embarrassed to admit I cannot recall what the two circled holes are for.  Can anyone remind me what the two circled holes are used for? They appear to be partially (but not entirely) covered by the fuel tank mounting flange.

I believe the larger dia hole in the middle is for the fuel sending unit wire.

Also, is the small dia hole (indicated by the arrow) for some sort of grounding wire?

Thanks.

PO installation of a trailer hitch.Fairly common in the 60's and early 70's.

[Angela]

Thanks Bob. Interesting. I wish I'd realized this before paint. :-(

I am not sure how I'm going to "plug" these holes given body & paint work is completed. Perhaps I can find a rubber body plug to fit.

Do you agree the large dia hole in the center is the fuel sending unit wire?

Also, is the very small hole noted with the arrow for some sort of grounding wire for something?

[Bob Gaines]

Thanks Bob. Interesting. I wish I'd realized this before paint. :-(

I am not sure how I'm going to "plug" these holes given body & paint work is completed. Perhaps I can find a rubber body plug to fit.

Do you agree the large dia hole in the center is the fuel sending unit wire?

Also, is the very small hole noted with the arrow for some sort of grounding wire for something?

Someone else will have to give confirmation on the other holes. 1970 is not my typical year of interest so I can't be sure of the other holes just the trailer hitch bolt pattern which is the same 65-70 Mustang .

[J_Speegle]

Thanks Bob. Interesting. I wish I'd realized this before paint. :-(

I am not sure how I'm going to "plug" these holes given body & paint work is completed. Perhaps I can find a rubber body plug to fit.

Might want to hunt down hard plastic plugs with the thin sharp edges and paint then to match the floor pan color on the undercarriage so they don't stand out as much. from a distance they may not stand out that way against everything else in the somewhat darker undercarriage

Do you agree the large dia hole in the center is the fuel sending unit wire?

For your year and car - Yes

Also, is the very small hole noted with the arrow for some sort of grounding wire for something?

Not for some ground wire. Instead it appears to be a screw holes that holds a rubber coated J clip (thing like the ones that often are attached to the top of the drivers side engine valve cover) that held the end of the fuel sender wire at the pass through hole

[Angela]

Thanks Jeff!  I can't visualize the J-clip you're referring to. If anyone has an idea of what type of clip this is, I'd appreciate the help (PN, picture, etc).  I would expect there to be interference with this clip and the fuel tank mounting flange?

[jwc66k]

Thanks Jeff!  I can't visualize the J-clip you're referring to. If anyone has an idea of what type of clip this is, I'd appreciate the help (PN, picture, etc).  I would expect there to be interference with this clip and the fuel tank mounting flange?

Once again, refer to the "Mustang Hardware Spreadsheet 69-70" by application (AP06.XLSX) in the library.
(Hint: "Wiring Harn,Fuel Level-Body@Trunk -".)
Jim

[jwc66k]

1970 is not my typical year of interest so I can't be sure of the other holes just the trailer hitch bolt pattern which is the same 65-70 Mustang .

I had a 1969 Mustang Sportsroof that I added a hitch to. Same two holes in front of the gas tank. There were two more holes in the bumper as well. It was for towing a fiberglass dune buggy: Pismo Beach, Marina Beach, Italian Bar in the Sierras were a few place the "gang" went. Fold down the rear seat, flip up the trap door, fold the passenger's seat forward, stuff the clothes bag in the gap and spread out the sleeping bag for over nighters. It was tight (I'm 6 foot) but doable.
In that time period, Mustangs were just another car used for commutes, shopping, travels. It was a fun car.
Jim

[Bob Gaines]

I had a 1969 Mustang Sportsroof that I added a hitch to. Same two holes in front of the gas tank. There were two more holes in the bumper as well. It was for towing a fiberglass dune buggy: Pismo Beach, Marina Beach, Italian Bar in the Sierras were a few place the "gang" went. Fold down the rear seat, flip up the trap door, fold the passenger's seat forward, stuff the clothes bag in the gap and spread out the sleeping bag for over nighters. It was tight (I'm 6 foot) but doable.
In that time period, Mustangs were just another car used for commutes, shopping, travels. It was a fun car.
Jim

Pretty common story except most didn't tow something cool like a Dune Buggy ,Cobra , name your poison, etc. I knew some people that only installed them a a status symbol of multiple options (before CB radios) and didn't even pull anything. Just had it so they could if they had to.   

[Bossbill]

You'll know if it was actually used since not only did it tie into the bumper but some into the taillight panel as well. The resulting damage to the body can be severe.

[Bob Gaines]

You'll know if it was actually used since not only did it tie into the bumper but some into the taillight panel as well. The resulting damage to the body can be severe.

All of the ones I am familiar with attached in the holes like in the picture and the rear bumper only. Not disputing your observation just that the tail panel was not the typical attachment point from the many I have observed over the years.

[J_Speegle]

Thanks Jeff!  I can't visualize the J-clip you're referring to. If anyone has an idea of what type of clip this is, I'd appreciate the help (PN, picture, etc).  I would expect there to be interference with this clip and the fuel tank mounting flange?

Looks like

https://www.npdlink.com/product/wire-j-clip-oil-sending-unit/167442?backurl=search%2Fproducts%3Fsearch_terms%3Dfuel%252Bline%252Bwire%252Bclip%252B%26top_parent%3D200001%26year%3D1970&year=1970

Don't have a 70 at home to check but this may has been added after the tank was installed so it would not interfere

 

[Crgjohnson]

If your tank is still out you can go ahead and weld up those two holes and then get a aerosol can of single stage body color from paintscratch.com. Since this area is not very visible I think your repair would be acceptable

Craig

[jwc66k]

Looks like

https://www.npdlink.com/product/wire-j-clip-oil-sending-unit/167442?backurl=search%2Fproducts%3Fsearch_terms%3Dfuel%252Bline%252Bwire%252Bclip%252B%26top_parent%3D200001%26year%3D1970&year=1970

Don't have a 70 at home to check but this may has been added after the tank was installed so it would not interfere

It's "Similar" to the NPD listed part, 353547-S2, which was used on 1969-70 small block LH valve covers. The correct Ford hardware part number is 381645-S100. It's unique in that it has a "dip" downward just after the mounting hole, then returns to the flat before the "J" hook.
See attached.
Drawing from "Ford Standard and Utilities Parts Catalog, January 1969" (AM0205 pg41). Application is from "1970 Mustang Electrical Assembly Manual" (AM0033 pg42).
Jim

[specialed]

Unique tank wire sender holder j strap (and not been repoed yet that i know of anyway) these j straps were held in place useing the tank mounting screws not screwed to the trunk floor so that small hole in center i think was added maybe a grounding wire or something or electric fuel pump.