[02S281]

anyone install a tach and use that tach adapter from autometer? Its pretty fucking confusing and i don't understand their directions since they are oh so detailed haha

Any help is much appreciated

[2002GTblkonblk]

I would like to put a tach in also, is it hard?? Someone help us!!!

[02S281]

bump..... anyone out there? Is there another post out there that someone could point me to?

[HMUSN]

which auto meter tach?

they have install instructions for each one on their site..

[02S281]

the tach itself is easy, its that stupid tach adapter that makes no sense....

[White99stang]

its pretty damn easy, if i can remember the color to all the wires i would have you set, what color are the wires coming out of the tach adapter

[White99stang]

and if you don't know what the tach adapter is actually doing i will explain it real quick. Its just sampling the 12v sine wave pulse that is going to your coils and converting it to a 12v square wave pulse and sending that square wave pulse out the one wire that connects to the tach signal on the tachometer. Then its sending the 12v sine wave pulse after it sampled it back down to the wire and then continued on to the cop's.

[02S281]

yeah i don't know the colors off the top of my head sorry. I will check when i get home from work. I thought it was pretty simple but the instructions pretty much suck.

Did you mount the adapter inside the car or on the firewall somewhere?

[cliffyk]

First, disconnect the battery!!!

You need to cut the red wire at pin 34 of connector C133, and then connect the red wire from the adapter to the red wire coming from the connector. The red/green wire from the adapter connects to the red wire that enters the harness.





C133 has a bolt clamping it together that needs to be removed before you can remove the plastic cover.

The red wire is the constant +12V feed to the COPs primary windings. The COPS are fired by the PCM's switching them to ground to allow the coil to saturate, and then breaking the ground connection when it's time to fire the plug.

The rapidly collapsing magnetic field generates a high voltage in the COP's secondary winding.

All of this high frequency/high voltage activity creates EMI/RFI switching "noise", at a frequency relative to the COP's firing, in the +12V supply to the coils. The tach adapter senses this switching noise and uses it to generate a clean trigger signal for the tachometer.

My Cobra radar detector uses this "noise" found in the cigar lighter power supply to switch itself to standby when the engine is idling, and off when the engine is stopped...