Let's play "name that wire!". Should be an easy one...

[Grec]

Car was originally a '73 340 Challenger Rallye.

I'm looking at a single white or grey w/black stripe wire that is coming through the firewall, in it's own rubber grommet, from behind my power braker booster.

My fingers are crossed that this is my original tach lead as mine has been disconnected... along with 100 other "modifications" that Bubba made before I got it. :-)

What do you think?

[JayBee]

Well, I looked at my '70 service manual and grey with tracer (18GY*) is definately for the tach BUT it doesn't go through the firewall with it's own grommet, but rather to the bulkhead connector. Then I looked at other models (Valiant & Belvedere) wiring diagrams and they showed 18GY* going to the tach through it's own grommet. Hope this helps somewhat, remembering that I only have "70 wiring diagrams....John

[Grec]

Well.. it doesn't disprove my theory... so that's kind of progress. :-)

Another disconneted wire in the area would be the lead to the oil sender... which Bubba had replaced with one of those deals that actually sends oil to a guage cluster in the interior. 

That's gone, of course, but my sender still isn't hooked up.

I've got a 73 Chally wiring diagram, but for the life of me I can't find the tach listed anywhere...

Note: Lol. I had tried to type in word for male rooster/male member+pit and it kept changing it to "thingypit"! 

[cudabob496]

diagram for my 72 Cuda shows a 20GY going through the firewall to the tach.

[Chryco Psycho]

I agree it should be the tach wire to the - coil

[Bullitt-]

I kinda like GEORGE for stripped wires...or perhaps ALVIN... of course the generic SOB works too 

[Grec]

Right on.  Thanks, guys.