Mystery ground wire

[TroutFJ]

Hey folks. I'm getting Babe all out back together and things are going pretty well overall!

Last night while installing the new carb I noticed this wire at the back of the engine bay coming off a screw to the firewall. It's black with a yellow stripe and from what I can see it's a ground. The problem is I can't figure out where it goes to. I checked pics I took before dismanteling but none show where it goes. I also looked through the engine bay wiring diagram but couldn't trace anything to this location.

Do you guys have any ideas?? '87 60 btw.

 

[Output Shaft]

That's a ground wire to the head.
Bolt one end of it to the passenger side of the head near the rear. You'll see an unused threaded hole. The other bolts to the body near the heater valve.

The head needs to be grounded for the spark plugs and temperature sender to work. Although the head is (or should be) grounded to the block via the head bolts, and the block is (or should be) grounded to the body & battery, it's never a bad thing to have multiple paths to ground in case something screwy happens.

 

[TroutFJ]

Awesome thanks!! I was swinging the wire around the engine bay looking for a terminal for it within that arc lol. The terminal on the screw faces the drivers side so I didn't think to look down lol.