help w/tach install

[probe em]

Hi all, this is my first post here on mx-3. I come in peace!
Anyway I've been working at a custom shop for over a year now and not many jobs throw me for a loop, but this one definately does. A customer with an mx-3 brought an APC tach to us to install. One of the other techs(who has never installed a tach b4) originally installed it, and it didn't function properly. So they told the customer that he would probably have to buy a tach driver, which I had the pleasure of hooking up. After I did that, it still didn't work. This time we realized that the needle on the tach was bad, however when the customer brought us a new one, it still didn't function properly. I'd really like to get this thing functioning properly, the customer seems like a really nice guy, and I'd like him to go away happy... we've also started installing a body kit for this guy, which again was not completed. The kit was fiberglass and requires a lot of modification for proper fitment, and this guy can't give us his car for a long enough period of time for us to fix it; it is his daily driver.

Anyway, I tried two things yesterday, one of them was grabbing the tach signal at the disty and going directly to the tach, and the other was running it through the driver. Both ways will send a signal to the tach however when I start the car it tach moves to about 100-200 rpm, and when I rev the car up, it doesn't exceed 1,000rpm. I set the tach itself up for a 6 cylinder, and when it didn't work, I tried the 4 and 8 cylinder option, and still the same thing.
After searching this board, I noticed that a few of you have gone right off the instrument cluster... is this with or with out the tach driver? also if any of you remember which wire you tapped, a heads up would be appreciated.

[MAZDABLOOD]

take the tach and flip it over with face down.now look toward your left side where the top plug is now right around that spot you will see the letter t with a screw that's your take lead and no you don't need a driver

[MAZDABLOOD]

i meant the cluster and tach lead

[Gro Harlem]

If you want to get the tach signal....look on the smaller of the two plugso n the distributor.

There is a 3 wire and a 6 wire plug. You want the MIDDLE wire on the 3 wire plug. That will give you the tach signal.

It should work if you tap into that.

[probe em]

Thanks Mazdablood, the customer finally came back to get it fixed... I connected the tach wire to the screw on the back of the cluster and it worked perfectly.