Are you using a points ignition or a HEI electronic ignition? Here is some info I dug up for you. It is critical to understand that the HEI requires 12 volts AT ALL TIMES to work at it’s best, and points would burn up with 12 volts at all times, so the factory added either a inline ballast resistor or a resistance type wire that reduces the 12 volts from the battery down to around 9.3 volts to the coil. The points-type distributors do use 12 volts when cranking, however, this is accomplished with a 'bypass wire', located between the starter solenoid (R) terminal and the coil (+) terminal, and is 'hot' only in the ignition switch's 'crank' position and "bypasses" the resistor wire to supply the 12 volts. In other words, on some cars, there will be 2 wires for spark juice, one is 'hot' in the ignition switch "crank" position, the other is 'hot' in the ignition switch "run" position. This was common in the pre-1971 cars, which used an inline ballast resistor with an external voltage regulator. So if you have changed your ignition to an HEI it could be a inline ballast resistor or a resistance type wire lowering your volts to 9.3 to accommodate a points ignition system. If not I would check into all wiring and then a new ignition switch.
1 - 4 of 4 Posts
If you turn the key to 'ON', then go under the car and jump the 2 posts with a screwdriver, will the starter turn? If so, then your 40 year old connections aren't delivering enough juice to your solenoid.... 9.3 volts isn't enough.
Solution 1... Refresh all the connections in your ignition circuit.
Solution 2... Use your weak ignition wire to activate a ford solenoid that is connected directly your battery to give your GM solenoid the full 12 volts it needs to do its job... It works the same as a headlight relay, uses low power to connect to a higher voltage source.
HEI's will work fine on lower voltages, just maybe a hiccup at high RPM, so I doubt thats your problem
1 - 4 of 4 Posts
