[2500HD]

Originally Posted by Andy4639

The alternator doesn't make the truck run rough. It was showing 12.4 at idle right. What did it show when you speed it up? Hold the throttle at about 2 grand and see what it reads. 12.4 at idle ant that bad of voltage. The alternator has to get spinning good before it kicks in and puts out. The alternator doesn't make a idle bad or good. Take a voltmeter and put on the battery and rev it up around 2 grand and see what it tells you.
Bad idle is a vacum leak or distributor problem on the older motors. Grounds can make things happen to.

I am starting to wonder if i hooked up the Pertronix correctly. I ran 12 volt from the IGN on the fuse box to the ignitor and to the new factory replacement coil. Should i have left the resistor wire in place so the coil would only receive araound 9 to 10 volts while running? Would the coil cause my problem after continued 12 volt use?

I did not rev the engine while checking the voltage. I thought i should have 14 to 15 volts while at idle.