tach install questions

[DRobb's_85]

I got a tach recently and today tried to install it on my 85 chevy. Should of taken all of 30 minutes but of course it didnt work out that way. The tach has 4 wires, red which is for 12 v. power, green which hooks to the distributor, black for ground, and white for tach illumination. My questions is how and where do I hook these up right? I took advice from a buddy and got some "female spade connectors" and crimped them on all the wires. He told me that they should just plug right in. He told me to plug the red (power) wire into the fuse box spot that says IGN. On my fuse box it doesnt even look like the spade connectors would plug in to those ports on the fuse box. I tried plugging the red one in IGN and it sorta felt like it plugged in but still didnt look right. Then I tried plugging the white one in the LPS spot on my fuse box. Wouldnt plug in at all..Finally I ran the green wire out to the distributor and found the part that says "tach" on it. Took forever with a mirror to get in there and tried plugging it in but it just didnt feel right. So I hopped in the truck and turned the key and of course the tach did nothing. I played with the wires and everything but nothing..Am I using the right connectors and am I plugging them in the right spots? Heres some pics of what I saw today..Where on the fuse box do I plug them in and what do I use? Theres also a pic of the white wire which had the spade connector on it..Those the right ones? Thanks

[68c10owner]

I just did one on my 84. The green went to the HEI, the black went to a ground under the dash. The white went for lights but mine already had aftermarket gauges under the dash so I just tapped into the white wire there. For the red I had to use a male spade and I found a terminal that was hot with the key on. Plugged it in and fired it up and it worked. I`ll see if I can take pic tomorrow if you don`t have it figured out by then.

[sdavid]

I have even crimped the red and white together and hooked both to a keyed 12V source. Light in the tach comes on with the key, but does not hurt anything. You have the green wire correct. Just takes some work to get it to hook up. Black just needs to be to a body ground somewhere. I normally use a small bolt on the gas pedal bracket. Looks like a triangle with 3 bolts on it, but you can use any decent one you can get the wire to.

[enaberif]

Most of our trucks have a grounding block under the dash on the left side and has about 6 spots.

And if you look at your fuse block up near the top you'll see one labelled "Acc" this is for accessories like your tach.