i threw this q up in the electric forum, and didnt get a response...... i want to hook up a tach on my drivers side a piller, and i just need some wiring tips, maybe somebody that has done it, thanks guys....

 

You could check out AutoMeter's website. They have instructions posted online for a lot of their gauges.

 

Gray connector of the ignition coil; find the black/white wire. Strip back some of the insulation. Twist another wire in and solder them together, tape 'em up. That's your tach lead.

Drill a hole in the firewall, put a grommet in it (bag of grommets for $1.25 from Radio Shack), and you're set. Run power to the "ignition" tap on the back of the fuse box. Run your ground thru the firewall hole and ground the tach somewhere near your battery (drill a hole in the frame with a self tapping screw and crimp a ring terminal onto the wire). Hook the illumination light up to the shift light in the console (easiest to get to). If you want to be able to dim your tach with your inside lights (I drive with all my lights dimmed way down), find the gray dimmer wire off your radio harness.

 

Here's what I did. I hooked the tach lead to the solid black wire coming off the black connector on the coil. Don't use a splice, it will wreck the wire (trust me, I just replaced mine yesterday). There's actually a large hole in the firewall already that you can use. If you look under the hood it's below the fuel pump relay and right in the rear and sidemost corner. You can follow it to the interior.

I spliced into the gauge power on the fuse box for power, connected to a ground just below the steering column, and spliced into the headlight switch wire after the dimmer. But even though I did it, I don't recommend splicing if you can avoid it. And make sure if you are splicing in around the fuse box that you do so after the fuse, not between the battery and the fuse. Good luck, and it's not too difficult.

I think later I'll post a pic of tach mounting. It looks pretty good.

 

lol I knew someone would have something a lot more helpful than I had to say.

 

What's cool is that the coil acts as a "bridge" for the two connectors. Pin "A" of the gray plug is connected "internally" to Pin "A" of the black plug. Same goes for both plug's pin "B".

So black/white on the gray connector is connected directly (from inside the coil) to solid black of the black connector.... so if anyone wonders why TomP and camaro_junkie gave two different wires off of the spark coil, the "real" answer is that both are technically the same wire.

And good point, camaro_junkie, on the blue splice connectors. That's what I used originally (back in 1994 when I put the tach in). A few years later, from all the engine vibration, that splice connector had "cut" thru all but 2 of the copper strands of the wire. The car stalled out on me, and I limped to the side of the road, and started wiggling wires and trying to restart it. I found that if I wiggled my splice, the car died. Went straight back home and fixed the connection like I should've in the first place- solder & heat shrink.

 

That's too funny Tom. I replaced the black and grey plugs yesterday because I broke off the hold-down clips a long time ago, and they won't stay on the new coil. But when I was taking off the tach lead I had 2 strands left. On my way home today I just thought of a good way to insulate it properly after soldering the lead on. So I'll do that next weekend. It's disconnected right now.

 

I've gotta change out my gray connector- or put some extra wire on it. Because of my "repair", if I unplug the MSD and plug in the stock coil, the wires strain- the one wire is now too short. I've been looking for the "perfect shape" one in a junkyard; local parts stores want too damn much for each connector ($20)!

 

It's too bad I am not at home right now Tom cause when I was not as knowledgable as I am now about my car I had the Chevy dealer replace my coil and connectors to it. On the invoice I have the part number for those connectors, you could see if GMpartsdirect has them cheaper.

 

If ya think of it, let us know those part #'s!! (I forget to look up so many things when I get home, it sucks... I should really not go on thirdgen.org during the day )

 

The way I remember part #'s is I bought that Camaro Parts and Illustration CD and have a database of part #'s. I sometimes bring it in with me to show the parts guys what I want. I put down part #'s in a microsoft word file and also keep them in e-mails I get from GMpartsdirect. That way if I want to bring up a part number I usually have it. I won't be able to see the # for the connectors till I go home from school which is another 2 weeks. Just try e-mailing GMpartsdirect, they should be able to get the # for you.

 

The connector they listed on my invoice was #12101896 ($11.37 GMpartsdirect) and the picture is a gray connector which I attached. The wire they used was #12048976 ($9.53 GMpartsdirect). I don't know what the wire really is maybe it includes the other connector with it I would assume. Hope that helps you out Tom.

 

#12101896 I forgot to attach it