73/87 LMC Tach Conversion wiring instructions

[slayton72]

Any one have instructions for one of these kits? I bought an 85 gmc project with most if not all of the LMC kit. Struggling with how to wire it. Any help would be appreciated! LMC was of no help

 

[Fastereddie]

Any one have instructions for one of these kits? I bought an 85 gmc project with most if not all of the LMC kit. Struggling with how to wire it. Any help would be appreciated! LMC was of no help

It should come with a stand alone harness

 

[slayton72]

there is... one plug for the tach.. a lead for the distributer.. and three other plugs for I'm not sure what? light switch?

 

[slayton72]

there is... one plug for the tach.. a lead for the distributer.. and three other plugs for I'm not sure what? light switch?

 

[Fastereddie]

there is... one plug for the tach.. a lead for the distributer.. and three other plugs for I'm not sure what? light switch?

It’s been a minute since I did mine. Let me see if I can find any papers

 

[Fastereddie]

I can’t find any papers so far.
I can look at my truck in a bit for ya.
I think there’s a ground and a 12 volt for under the dash

 

[bradshawtech]

You’ve got the best of the best here on the site, more detailed description including colors and grouping colors and number of conductors.

 

[Fastereddie]

Found a pic of the back of the tach. 3 pins so yeah that would be it. One goes to ground, the other to 12v ign. hot, and one to the tach signal. If you have an HEI distributor there is a spot for it to plug in.

 

[Big Ray]

Green-tach connecter on distributor
(HEI)
Black-ground
Pink or whatever-accy plug in fuse panel.

They sent me the wrong harness, so I had to cut the connector off the power plug and crimp on a connector to fit the fuse panel.

 

[Big Ray]

helpful tip: don't tighten the tach so tight the circuit board touches the mounting bracket.
Sent my tach crazy...
I let mine float and tightened it with the front mounting screws that hold it in the bezel.

FYI for anyone else contemplating doing this: buy the parts separately. It cost a lot less than the kit.