Pertronix and factory tach....compatable??

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Pertronix and factory tach....compatable?? #1338631 11/20/12 09:56 PM 11/20/12 09:56 PM
Joined: Jan 2003 Posts: 1,567 Ky J jt4406 OP pro stock
jt4406 OP pro stock J Joined: Jan 2003 Posts: 1,567 Ky	Good friend has a nice 70 Cuda 340 car that he has restored and has installed an aftermarket electronic ignition (maybe Crane). It uses all original external stuff, except it has two wires leading out of the distributor. Anyway, the car runs great, but the factory tach (ralley dash)doesn't work. Seems I remember issues with compatability, anyone know? jess Last edited by jt4406; 11/20/12 11:06 PM. Yeah, it's hopped up to over 160...

Re: Pertronix and factory tach....compatable?? [Re: jt4406] #1338632 11/21/12 12:57 AM 11/21/12 12:57 AM
Joined: Jan 2003 Posts: 15,882 Jefferson State S srt ESYC
srt ESYC S Joined: Jan 2003 Posts: 15,882 Jefferson State	I had the same problem and found info on the net that worked. Hook the tach into the (-) side of the coil and install a 11.5K 1/2 watt resistor (from radio shack) between tach and coil. The write-up said if that resistor does not make it work to try a 10k, 9k, and 7.5k. One should make it work.

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