The Stovebolt Site Forums The Shop Area The Electrical Bay Wiring Starter / HEI Bypass Conversion

Some info says how easy or one wire hookup about wiring an HEI to your truck and little about the related starter. Most times the starter does not enter into the info. The original wiring has a Bypass wire from the plus side of the coil to the starter 'R' post. This way the coil ''only in start mode'' has full 12volt positive at the coil. This standard wiring also has a resistor allowing about 9 += volts to the std. points dist. /coil during operation.
When wiring for an HEI a larger size wire 10-14 ga. should be placed to the HEI 'BAT' from the key switch ignition post and remove the resistor wire. I have also found notes on eliminating the 'Bypass' wire from 'R' to coil when installing an HEI.
Comments please...
Then we can talk about the relay for this circuit.
jim

The HEI does not NEED 10 gauge wire. In conversations with Tom Langdon, the wire size was increased from a "normal size" due to an occasional miss during emissions testing, not because the ampacity of a 10 gauge wire was needed.

My wife's uncle was an engineer for the Motorola automotive products divsion and was on the team which developed the hei module. He says that it will fire down to ~4V. I have found the output to decrease proportionally with voltage and still be plenty at well below 12V. I have found the average current draw to be ~2 amps at 12V.

Just wire it up to a switched 12V supply.

thanks for the info jason

The HEI always runs on 12v.. ya dont need a resistor anywhere...or worry about the starter... as long as the HEI terminal has 12v regardless of the key in ign or start.... dont wire it from the starter,,wire it from the switch......