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jrelliott · 12-04-2019, 05:59 PM

Conversion kit for GM 10SI and 12SI altenators to 1 wire
Quick Start SE-590

An alternative to the Single wire altenators which require revving the engine to get to charging, You can get a DA plug from NAPA or other vendor. Take the red wire on the DA plug which attaches to the F terminal on the alternator and attach a ring terminal to fit the HOT wire from the Alternator. On the second wire from the DA Plug (usually white in color) which goes to the R terminal on the alternator attach a moderate 3A/ 100V diode cathode side to the white wire from the DA plug. Attach several feet of wire to the anode (other end of the diode) and wire this to the coil (hot side) on your Model A. Cover the diode with heat-shrink tubing to prevent a short before attaching to the coil. Do not skip this step or use cheap tape. The diode is required or engine will not turn off. This set up is very inexpensive and will work on the single wire altenators also. What is nice about this modification is that you can get a replacement alternator anywhere and only have to change the pulley and you are ready to go. Have made this modification to several cars. Must put a fuse in system or battery will run down due to current being fed to fields of alternator when key off on Model A. Pull the fuse when
not running the car.

12-04-2019, 05:59 PM	#13
jrelliott Senior Member Join Date: May 2010 Location: Pine, AZ Posts: 794	Re: Alternator Replacement 12V Conversion kit for GM 10SI and 12SI altenators to 1 wire Quick Start SE-590 An alternative to the Single wire altenators which require revving the engine to get to charging, You can get a DA plug from NAPA or other vendor. Take the red wire on the DA plug which attaches to the F terminal on the alternator and attach a ring terminal to fit the HOT wire from the Alternator. On the second wire from the DA Plug (usually white in color) which goes to the R terminal on the alternator attach a moderate 3A/ 100V diode cathode side to the white wire from the DA plug. Attach several feet of wire to the anode (other end of the diode) and wire this to the coil (hot side) on your Model A. Cover the diode with heat-shrink tubing to prevent a short before attaching to the coil. Do not skip this step or use cheap tape. The diode is required or engine will not turn off. This set up is very inexpensive and will work on the single wire altenators also. What is nice about this modification is that you can get a replacement alternator anywhere and only have to change the pulley and you are ready to go. Have made this modification to several cars. Must put a fuse in system or battery will run down due to current being fed to fields of alternator when key off on Model A. Pull the fuse when not running the car.