68 GMC 3/4 ton what are these wire coming out the firewall?
 

Right around the harness connecter there are 3 single wires that come through the firewall. There was a 305 v6 in the truck originally. I figured out the lower wire was the factory tach but the 2 above I am not sure. The one toward the outside is hot all the time. The one closer to the inside powers up when the ignition is turns on.

Re: 68 GMC 3/4 ton what are these wire coming out the firewall?
 

I guess you are going to have to try and follow them and see where they go on each end. The one with the rubber grommet on it looks like it could be a tach wire but I don't think it would be hot all of the time.

LockDoc

Re: 68 GMC 3/4 ton what are these wire coming out the firewall?
 

Looks to me like the group that goes across the firewall with one wire dropping down to the coil (hei?), the others going over and dropping down into the wire clip behind the right head (clip bolts to the transmission bellhousing bolt) large with going to the starter, green wire to the temp. sending unit.
???
Kinda looks like it could be this??

Re: 68 GMC 3/4 ton what are these wire coming out the firewall?
 

I guess I was not clear enough. Sorry I am asking about the 2 single wires in the pic. One on the right with the grommet is contant hot and the one on the left with the grommet missing that has the butt connector coming out of the hole. This one powers up with key on. From the factory what were these two wires? Thanks The the long bed camper edition if it makes a difference.