Installing after market Tachometer questions

Cuse99

Master Mechanic
Dec 21, 2020
251
126
43
1984 Chevy El Camino, standard model. Small block V8, no computer (its been modified)

Hello Forum members. I bought an Autometer mini tach for my car and I could use some help to install it. I worked on cars in my youth but not in a while. If I have good instructions I can get this done, but I'm not a mechanic so please be kind. I can mount the unit and run wires and I can splice wires, no worries. I'm having trouble identifing which wires to splice to. 4 wires model.
1. Ground - no problem
2.Connect to HEI distributor - no problem

3. Hot wire, on with ignition only - could use some help
4. On with dash lighting - could use some help.

Any advice would be greatly appreciated. Thanks in advance.
 

SS_Malibu

Royal Smart Person
Supporting Member
Sep 27, 2021
1,099
1,917
113
Mesa, AZ
The ground goes to a good ground source.
The green wire (I think it is) goes to the tach connection on the HEI distributor.
The red wire (I think it is) goes to a hot fuse when the key is on in the fuse block under the dash by the brake pedal. Use a test light to see what fuse is hot when key is on and off when key is off. You should be able to put a female end on the wire and just plug it in. There will be a spot for this to plug in.
The white wire goes to the lights. You will need to pull the light switch and find the wires that operates the dimmer on the lights. Use a test light to see which wire dims. You can put a male connector on that wire and slip it in next to the dimmer wire.

This is what I did and it works great.
Hope this helps.
 
  • Like
  • Agree
Reactions: 4 users

melloelky

Comic Book Super Hero
Oct 22, 2017
4,108
9,405
113
mass
he's right^^the spot on the fuse block he's referring to will be next to a fuse where "ING" will be printed.that means it has power when the ignition is on and it's also protected with the fuse to next to it.there is a spot labeled "inst light" that will feed your white illumination wire. something like this:
 
  • Like
Reactions: 3 users

SS_Malibu

Royal Smart Person
Supporting Member
Sep 27, 2021
1,099
1,917
113
Mesa, AZ
he's right^^the spot on the fuse block he's referring to will be next to a fuse where "ING" will be printed.that means it has power when the ignition is on and it's also protected with the fuse to next to it.there is a spot labeled "inst light" that will feed your white illumination wire. something like this:
I forgot about the "ING" labeling.
 
  • Like
Reactions: 1 user

Cuse99

Master Mechanic
Dec 21, 2020
251
126
43
he's right^^the spot on the fuse block he's referring to will be next to a fuse where "ING" will be printed.that means it has power when the ignition is on and it's also protected with the fuse to next to it.there is a spot labeled "inst light" that will feed your white illumination wire. something like this:
That's good information, thank you. So how to I connect the wire to the fuse box? Is there a connector or adaptor?
 

melloelky

Comic Book Super Hero
Oct 22, 2017
4,108
9,405
113
mass
crimp on a male spade connector,it's a small flat blade that will press between those two spring loaded contacts.in a pinch you could flatten the wire and solder it flat and do the same thing press it between the contacts
 
  • Like
Reactions: 1 user

GBodyForum is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com. Amazon, the Amazon logo, AmazonSupply, and the AmazonSupply logo are trademarks of Amazon.com, Inc. or its affiliates.

Please support GBodyForum Sponsors

Classic Truck Consoles Dixie Restoration Depot UMI Performance

Contact [email protected] for info on becoming a sponsor