Dedicated Tach wire for wiring a Shift light.

[Blazzin Joe]

From what i was reading on autometers website their tachs have problems workging with the newer Coil Pack ignition systems.

They say that it will how ever work on the LS1 motors. Further digging (from their support) they said that using a SOLID WHITE wire located on PIN 8 of the Clear connector on the computer will provide a tach signal.

Now my question is, who has a clear connector on thier computers?!? Or if anyone else has some ideas about how to hook it up [img]smile.gif[/img] thanks.

[Wicked 3800 V6]

The tach wire is the most highly contested wire in the whole car. You can pull it from a number of places, and don't believe everything you hear / read from Autometer, boards, etc. Here's my take:
I tapped a random (got it 1st try) white wire from behind the gauge cluster, for the tach wire. I use it for my Harlan lite, and my Drag'N tach. Works great, except i have (hopefully unrelated) power trouble on the tach. In short, umm ... don't listen to autometer, and use the SEARCH FUNCTION (there must be at least 3 different ways folks have done it). You MAY be able to tap it at the computer, but I thought on the 3.8s the tach signal was ONLY behind the ICM not the PCM. Or tap it behind the gauges, like me, and it's already in the car.
Good luck, and i'm curious to see how it works out for you, as i've not yet cured my power trouble.
-Rob

[Blazzin Joe]

What kind of power problem are you having? Does the light come on when you turn on your blinkers or your wipers? I read on Ls1tech.com that ppl have had that problem with the harlan lite... Well let me go back and try to find the white wire you are talking about... i know i saw one under the dash so i can give that one a whirl [img]tongue.gif[/img] .... I will let you know how it works out [img]smile.gif[/img]

[Wicked 3800 V6]

Actually, I pulled the gauge cluster, and tapped a wire back there. Don't screw up and set the air bags off, though. And, BTW, darn near every wire around the dash is white, but in the group behind the gauge cluster, only a few were. Yeah, everytime I have the headlights or Radio on, the tach cuts on and off. Some sort of power problem -- not getting enough juice. Not sure what to do ... got it double grounded, might try grounding even more.
-Rob

[Blazzin Joe]

Well I found the correct TACH wire. Its located on the PCM... From the upper bundle of wires (the blue connector) PIN 8 is a Purple . Its the PCM tach signal. Use that to connect up your shift lite [img]smile.gif[/img]

Mine works like a champ... when out and ****ed around with it and what not... Give that a try.

[ May 12, 2002: Message edited by: Blazzin Joe ]</p>