12Volt switched + tach wiring.

-

unclepunchy

Well-Known Member
Joined
Jan 12, 2023
Messages
117
Reaction score
34
Location
Victoria, BC Canada
Hi folks,

Installing an aftermarket tach, 73 Duster.

I have my ground done and my green wire to negative coil. Can I use the following from my fuse panel for the 12 volt switched and the dimmer / / /instrument light?

F828602F-476B-431C-B1EC-58A1C90DA751.jpeg
 
The only "switched" in the fuse panel is ACC. This means if you are sitting listening to the radio, etc, the tach will be live. You CAN use that. Yes on the dimmer. Orange wiring coming off the INST fuse in the fuse panel.
 
I have the ballast bypassed. Running HEI
The wire that now feeds your HEI is the same wire ( most likely) but I agree you can use the output from the 3 ACC fuses. If you have an empty space you can get the connector and run a dedicated run to the tach maybe a 5 amp fuse and 18 awg wire.

But as noted by 67dart273 the tach will be live in run AND in ACC
 
I have the ballast bypassed. Running HEI. I just finished taping/tubing everything up nice and pretty and don’t really want to take it all apart… yet.
Since you had to run the ignition trigger into the tach, you could have run a (fused) wire off the coil + stud to power the tach
 
IIRC that's how Chrysler powered the tach on some years/models/.
This is 67 dart
Green goes to coil
Purple with trace is backup lights
Orange is inst cluster / back light / prndl lights and gets power from rheostat.
Black is ground
Yellow gets power from a post on the wiper switch. ( Switched or always on???)

I think this diagram has an error.

I think purple with that trace is the wire getting power from the wiper switch
And yellow is the output to the backup lights
.

Making wire getting power from the wiper switch the power for the tach.

Note thec1234 on the left does not mirror the 1234 on the right.

The Solid purpleon the right goes to the actual backup light bulbs

The white in the right god to a terminal on the wiper switch. ( Note the wiper switch is NOT switching any power to the white wire it is just a jumper of sorts.)
PXL_20230530_164008124.jpg
 
Last edited:
Dana.
In '67 the 18 ga dark blue with stripe wire from the optional fuse goes to the tach. At least for the Barracuda if had the optional tach.
1685466192845.png

The tach gets a signal from a gray wire in the harness. Lighting comes from the instrument panel lights.
The seperate tach in the console got lighting from an additional instrument panel lamp feed (orange) that was otherwise unused.

In '67 white from the Wiper Switch B terminal is power for the reverse. After that the connections vary.
I don't want to detrail this thread further since the OP has much newer model. But yes we agree power was tapped for the tach from the switched accessory fuses.

 
Last edited:
It is confusing when the factory used a terminal on a unrelated switch to provide power to other accessories



:rofl:

But I agree they changed a lot over the years but left other things alone. No ryhme or reason
 

-
Back
Top Bottom