Pertronix II Relay

69cobraman · 10-29-2012, 01:46 PM

This Pertronix II has been giving me fits since I installed (on two cars). Same issues on both cars. Fires up on cold engine fine. Runs rough after warming up and a real bitch to start when warm/hot. All my research shows the issue(s) are the resistor in the Ignition wire. So to keep this "Clean", I am opting for the Relay configuration.

Here is my question to all you professionals.

Should I use a SPST (Single Pole Single Throw) or, SPDT (Single Pole Double Throw)?

I plan on going direct to the constant power on my solenoid fuse that is hooked up to my single wire Alternator.

Thoughts PLEASE.

Cheers,
Rik

localfiend · 10-29-2012, 02:44 PM

You don't need a double throw relay - though it wouldn't hurt to use one (you'll just have an unused wire/post.

I bought a bunch of double throw relays and relay harneses cheap years ago so that I have them on hand. With all the old vehicles I end up messing with it's really handy.

Amazon.com: Parts Express 12 VDC 5-Pin Relay Socket: Car Electronics

Amazon.com: Absolute RLS125 12-VCD Automotive Relay SPDT 30/40A: Electronics

bartl · 10-29-2012, 02:48 PM

I'd do none of the above.... I'd simply bypass the resistance wire (leaving it in place) with a length of 12ga primary wire.

4mustangs · 10-30-2012, 04:08 PM

Quote:

Originally Posted by bartl

I'd do none of the above.... I'd simply bypass the resistance wire (leaving it in place) with a length of 12ga primary wire.

I'd do the same only after I tested with an alligator clip jumper to make sure this is the problem.

Ron

mph65k · 10-30-2012, 11:27 PM

How long is the actual resistor wire and did you just splice into the wire ahead of it? I installed a relay for the same reasons since my MSD distributor really wanted 12V. But now, of course, my rally pac won't work and I need to either run a new wire or do this bypass.

Huskinhano · 10-31-2012, 12:59 AM

On my 66, I have a fused #10 wire switched by a relay (SPST) feeding an aux fuse block. I unplugged my pink resistor wire from the bullet connector off ignition switch and connected the relay to ignition switch. I ran a #12 wire off the new fuse block to my HEI and a #14 to my electric choke. They both get a excellent source of power and work great. No voltage drop from all that factory wiring harness!

69cobraman · 11-12-2012, 02:32 PM

Finally completed the Relay installation this weekend for the Ignition Switch to Coil. So far so good. The car starts right up on both cold and hot engine easily. I need to do more testing after a hot Texas day. This may be the trick...

And LOCALFIEND- Thanks for the links. I used those and purchased a Relay that could tolerate water. Figured being under the hood, it would be useful.

Cheers,