Igition problem

[Lloyd C.]

Working on my son's 66 SWB which has a 350 V8 w/ an HEI distributor. I installed a brand new under dash wiring harness, fired it up and it ran great. However, this morning, it will fire when I crank it over, but immediately dies when the switch goes to the "Run" position. A mechanic friend said there may be a ballast resistor in the wiring harness that is toast. Since the HEI runs on 12 volts, is there a resistor somewhere in the under dash wiring harness that I can simply by-pass?

[rideblue00]

Is the original switch in place still? Try another ignition switch.

[fleetsidelarry]

in our trucks, the original wire that feeds power to the old coil IS the resistor. if you did not do so already, it needs to be bypassed and the HEI supplied with (as you said) a full 12 volts.

I was thinking the source for power to the distributor was the same in both the "start" and "run" position on the switch, suggesting, as rideblue mentioned, a switch problem?

[jjzepplin]

Sound like a switch to me too. I had this issue happen to me after replacing the top end on a 68 ford p/u with 460. Mysteriously the damn thing would crank and fire up and then die. Guy was getting kinda anxious with me and he was a big dude... Ended up being the ignition switch. Some things just happen I guess. These trucks are old so rule nothing out.

[Lloyd C.]

Thanks for the feedback, guys. My friend, Mr Goodwrench, also thought the resistor was an integral part of the wire that runs from the switch to the coil. So, last night I ran a by-pass wire and, shazam, it fires right up!

BTW, I really do know how to spell "Ignition"