Rallye dash Tachometer wiring

[Rocky_JS]

I am trying to hook up a factory tach in a rallye cluster. Which wire is 12v feed and which one is the pulse? If memory serves me I think the spade connector is the pulse and the stud is the 12v feed. Can anyone confirm?

John

 

[1970Duster]

This probably won't help. Of the remaining 3 not being you used, you have a 33.33333333% chance of getting it right and not frying the thing.
I take that back, that answer was of no help at all.

 

[Rocky_JS]

I kind of need to be certain. lol

The guy just spent 400+ on a restoration and upgrade. Yeah, I wouldn't have either but to each is own I guess.

I do not have a factory tach harness or it would be easy - grey to coil.

 

[67Dart273]

Actually, in this case hooking the 12v up to the wrong terminal won't hurt.

Found this

 

[Rocky_JS]

Right on, thanks! It is what I thought I just needed to be sure. Good to know that reversed wouldn't make a difference.

 

[RedFish]

when in doubt, Charlie out. pick C.
Silver sparks and gold is ground.
Those little things can help when you're not defusing a bomb ( risking 400 bucks qualifies LOL ).
The 12 volt wire for the tach goes into the backside of the fuse box and on the acc fuse.
I've got a pic of that connection here somewhere if needed.

 

[Rocky_JS]

Thanks Red. Kind of hard to fathom that they would use 12v to a spade but.... If you were wiring this would you go path of least resistance - direct to coil. Or go bulkhead in/out like the factory? I do have proper 56 connectors.

 

[RedFish]

12 volts to a spade but at least its fused. A clock in that pod got its 12 volts directly off the ALT' gauge stud without a fuse inline.
Tach signal wire went straight through the firewall with a rubber grommet same as the vacuum hose for the performance indicator did.
I guess its possible they moved it to the far right bulkhead connector with reverse lamp wires, etc.. in later than 69 models.
Considering that the oil sender wire is also grey and going to nearly the same location, I would route it, flag it, something, to help prevent it's ever finding the wrong connection.