I have wanted the tuner look in my car for sum time, so i bought a tacho :P anyways... i installed it and and finally got it working, after using the speedo sensor cable as a positive for it by accident and frying the speed sensor unit, and anyways... There are 4 wires to run with this unit, ground, positive, wire from distributor and dash lighting. i have installed the positive from acc. behind radio, the dash lighting one is connected to a wire behind the shroud where the dimmer, the ground is grounded DUH, and i ran a wire from the white wire on the plug which connects the distributor cap. it works fine in "Park" and "Neutral" but when im cruising along in drive or any other gear in my 4 spd auto it gets to around 2 1/2 grand then the need on my aftermarket tacho begins to bounce around all over the place,, have i done anything wrong??

Have you set it up for a 6 cylinder engine?

yeah, there is a switch on the back of the unit, and its on 6 cylinder.

So erm...you brought a rev guage?
Will need to tap into something that reads what the guage is ment to read
Maybe look in the workshop manual wiring diagrams to see which wires best
I think you have got your source wire in the wrong place

so when you rev in neutral, the stock tacho is saying 4500, and the aftermarket one also reads 4500?

You have an auto and bought an aftermarket tacho?

You have an auto and bought an aftermarket tacho?

+1 i dont know why people need to cheapen the looks of magnas by throwing ricer gear on, but meh their car, they can do what what they like. agree with above post sounds like source wire is wrong

Yeah, well in park or neutral, the aftermaket one reads the same as the one in the cluster, no problems, but as soon as you get to about 2100 in drive or any other gear, the needle on the tacho reads about 3000 and it jumps around ALOT i might be able to take a video of it for you.