Aftermarket Tach Connection

I need a direction to go to find a lead to tap into to feed a AutoMeter Tach. This is on a 99. There are two leads comming off of the coil that I tend to think would be where to look but I'm not sure. I don't want to fry this tach.

Whatchathink?

FNF

There should be an RPM wire on the PCM. If not I would look at the cam sensor and see if you can get a signal from that. If you have a timing light you can use it for testing purposes. Can you set the gauge for different # of cylinders?

I'll check the PCM today if I can. The tach can be set for 4, 6, & 8 cylinders. I guess I would be out of luck if I had a Viper:laugh2:. Thanks for the help.

FNF

On a 99 there will be no RPM wire on the PCM, as far as I know... otherwise, you should be able to get a signal off the INPUT of the ignition coil. One wire will be +12V from the ASD relay, the other is an interrupted ground signal from the ECU. You may have to do some signal conditioning before feeding the signal to the autometer gauge, I have no experience with them so I can't really tell you for sure.

Clearly using the output of the ignition coil will be bad :explosion