Tach and Pertronix II

[lloyd70cs]

Hi guys,

I know this topic has some extensive posts but here is my question nonetheless as I am clueless with electrical. On the positive I just wired up an aftermarket tach without screwing up anything. I have a 1970 F250 2wd Camper Special. Said tach installed with green wire to coil, black to ground, red to third spot on pigtail behind ignition, white to some other wire for backlighting.

The pertronix II wants a wire to bypass resistance wire to ignition for optimal performance besides the red and black to coil.

My question is where should this wire go to? Thanks

[sargentrs]

I like to install a relay to pull power straight from the battery. If not, look for an orange wire with a bullet connector laying on the driver's side of the intake btween the carb and the valve cover. It's for the optional carb solenoid. My '70 had it and I ignored it for years till one day I was looking for a switched hot source when I installed an electric choke.

[lloyd70cs]

Thank you, again Randy.

[lloyd70cs]

Apparently no solenoid wiring on mine. I should be able to wire to same spot tach is wired, no? The third spot on pigtail behind ignition?

[sargentrs]

You will only get 9-10v there. It is connected to the resistor wire. To use that wire, you will have to remove/bypass the resistor wire. That is the most common wiring mod suggested that comes with most aftermarket electronic systems. Other options are to come from the fuse box or you can splice into any switched source like the radio. I like to use the relay method because at minimum I can pick up 2 switched curcuits for accessories. https://youtu.be/s7npq2HVszM

[lloyd70cs]

Hi Randy

Watched your video and read some more. So if I make a bullet connection at that 3rd opening and wire to a relay that is my switched connection? Then just a fused wire to battery and red wire from pertronix to relay accessory terminal? Do I need to also do this with the coil? Thanks

Lloyd

[sargentrs]

Yes, you should. I like to run a wire from the relay to the "I" terminal on the solenoid and then from there to the "+" terminal on the coil. You really need a hotter coil too. They recommend the FlameThrower and kits sometimes include it. Accel and MSD also make similar coils. In addition, I recommend increasing your plug gap to .040-.042 and using 8mm performance wires. The electronic ignition systems perform much better and you should upgrade the whole shebang to get the most out of it. Just as a side note, I personally have had a bad experience with a Pertronix on my '64 Fairlane. I had 2 burn out on me in the space of 4 weeks. Switched to a Ford Duraspark system and had no more problems. You'll find good/bad experiences either way but that's just what happened to me. One last thing, if you get the Igniter I vs the Igniter II, don't leave your ignition key on unless the engine is running or you will fry the module. It's a known problem with the Igniter I that was corrected in the Igniter II.

[lloyd70cs]

Sorry to be so daft. Can I just wire to coil from module like normal and then send a wire to relay from there for both the coil and module together? And leave the resistor wire intact cause it is bypassed?

[sargentrs]

I feel you should keep the 2 circuits separated. 1 wire to the module and the 2nd wire to the coil. The Pertronix requires a consistent voltage to run and I don't like the idea of something else in the loop to possibly interfere with it's power source. No need to mess with the resistor wire as it's just providing the trigger to the relay.

[lloyd70cs]

that makes sense. I will wire them up individually to the two accessory ports on the relay. thank you again!

[sargentrs]

Let us know how she turns out. Inquiring minds wanna know.

BTW: You can leave your original ignition wire attached to the solenoid. When I did mine I cut the wire from the original distributor to the 3 prong plug in half and added
a bullet connector jumper wire. Then put a bullet on the Pertronix and a bullet on the old distributor wire. Then after I removed the old distributor, I packed it up with the cap and plug wires still attached and put it in a box in my toolbox. If the new setup ever crapped out just pull out the old distributor and new distributor, unplug the new wire from the original circuit, install the points distributor and plug it back into the harness. Emergency points ignition replacement kit!

[lloyd70cs]

Thanks, I will post here if/when it works out for sure. Hopefully this can help someone else out somewhat. Does this look right to you Randy?

[lloyd70cs]

Nevermind about the about drawing. I spoke with Pertronix and the said to do it like this:

Ignitor Wiring 2.jpg

And to use 14-16 gauge wiring all around. Hope this helps someone else sometime!

[sargentrs]

I routed a little differently but it's the same effect. I went from the module to the "I" terminal on the solenoid and then from the solenoid to the coil +. Bout the same.