Easiest way to wire up factory tach?
 

I'd rather not spend ~$25 to buy a tach harness if I can help it.

Checking to see if this is the correct/easiest way to wire up a tach in my 70 GMC Jimmy. Single wire run to the HEI tach post through the firewall and the other 2 (12V and ground) wires stay local like in the pics below that I found on the forum from older posts.

Thanks.

Re: Easiest way to wire up factory tach?
 

Just run the hot wire to fuse block to unfused 12 volts. You can do it that way but it may not be as good of connection.:chevy:

Re: Easiest way to wire up factory tach?
 

The tach wiring should be at least 14 gauge but 12 is preferred.

Do not tap tach wiring to the cluster hot feed. It is only 18 gauge and the tach needs 12 gauge wire.

The tach will ground to the cluster tin so really no external ground is needed but never hurts. Run the battery voltage directly to fuse panel "ign feed" with 12 gauge wire. Also 12 gauge to the neg side of coil.

Re: Easiest way to wire up factory tach?
 

Cluster Feed or Ign Unfused for the tach power?

Thanks for the update. I can easily update the wire gauge and connections now that I have everything apart. ;)