Feeding a wire through firewall

[Bleep Bleep]

I’m looking for option(s) for where to feed a single wire through the firewall on a 1969 RR. Thoughts guys?

 

[dadsbee]

Any existing grommet, or the unused ports on the bulkhead connector block.

 

[zyzzyx]

Yeah, I used a blank position on my bulkhead connectors. Just make sure you jot down what it is somewhere!

 

[LowBikeMike]

Lots of options. Several divots for such between master cylinder and bulkhead connector.

 

[Bleep Bleep]

Thanks. Brand new to this. Sad, but I am not sure specifically where you’re talking about.

 

[Bleep Bleep]

Thanks. Brand new to this. Sad, but I am not sure specifically where you’re talking about.

View attachment 1732333

I’m hooking up a Sun tach and am running the sensing wire to the coil.

 

[LowBikeMike]

The divot you see to the right of the grommet is designed for the tach wire and 7/8 grommet on a 69 RR. Sadly the idiot before me that punched the hole in my firewall didn't pay attention to the proper way of doing things.

 

[Bleep Bleep]

The divot you see to the right of the grommet is designed for the tach wire and 7/8 grommet on a 69 RR. Sadly the idiot before me that punched the hole in my firewall didn't pay attention to the proper way of doing things.

View attachment 1732353

I’m a little anxious over making any holes in the firewall. 7/8ths grommet = drill 7/8ths hole? I can get any grommet at an Autozone, etc?

 

[LowBikeMike]

This is probably the most helpful for your situation, with pictures. The M&H harness they refer to has all the wires you would need, most likely even for your aftermarket tach.

Factory tach question(s)...

You can certainly drill a smaller hole, if you use this harness or parts of it your firewall will retain a factory appearance. Before I drill any hole I find a grommet and then drill. Drill at the dimple regardless of size, at least then its in the right place.

 

[Bleep Bleep]

Thanks! This does help. I assume the dimples are placed where it’s safe/open to drill through.

 

[Crackedback]

Auto car, use the clutch rod plug

No drilling of the firewall required

 

[BLK 68 R/T]

Thanks. Brand new to this. Sad, but I am not sure specifically where you’re talking about.

View attachment 1732333

This part is the bulkhead connection. Pick an empty port and use it. Probably can run a small gauge wire all the way straight though if you want. Or get some male and female packard 56 connectors and do it halfway factory style. No drilling needed.

 

[68BabyBlue]

I like the bulkhead connector option, and so will your wife, if she ever has to auction the car.

 

[68BabyBlue]

Auto car, use the clutch rod plug

No drilling of the firewall required

Yes, but it’s a 4 speed.

 

[Triplegreen500]

Find any rubber grommet.

Un-bend a metal coat hangar so you have a long "poke-tool".

Tape the wire to one end of the hangar so it won't come off when you shove it through the grommet.

Poke hole with coat hangar (make sure not to nick any wires), and push it into the engine bay until you can grab it and pull it the rest of the way through.

If you taped the wire to it correctly, the wire will come through as well. Untape it, pull it through, and route it as needed.

 

[Bleep Bleep]

Thank you. My problem is I can’t find any exposed grommets anywhere on the firewall? Is there access between inside and engine bay behind any of the electric blocks mounted to the firewall. Not that would solve my problem though.
I’m trying not to cut any new holes if avoidable.

 

[Geetex]

Thank you. My problem is I can’t find any exposed grommets anywhere on the firewall? Is there access between inside and engine bay behind any of the electric blocks mounted to the firewall. Not that would solve my problem though.
I’m trying not to cut any new holes if avoidable.

Post #12 is the answer that you're looking for. If you don't understand it, I'm sure @BLK 68 R/T would welcome a private message from you to help explain anything you don't understand. Or if you look at your car, compare the picture in post #12 to your car, and still can't figure it out, come back here and ask more questions on this thread.

 

[dadsbee]

Post #2, Post #12 and every car has a speedometer cable grommet !

 

[68_661charger]

I run a single wire through one of the pins that hold the firewall insulation up. The pins are hollow for the most part so a small drill bit from the inside drills out the end of the plastic pin.

 

[BLK 68 R/T]

I run a single wire through one of the pins that hold the firewall insulation up. The pins are hollow for the most part so a small drill bit from the inside drills out the end of the plastic pin.

Very clever!