LS3 coils and alternator wiring on EMU Pro 8

EMU PRO
1

Hi,

as mentioned in the title, I’ve got two questions on how to wire an LS3 engine:

  1. LS3 coils got seperate grounds, one is reffered to as low reference or signal ground. With original Chevy wiring those grounds go back into the ECU. So am I right to put these to the digital ground pin on the EMU Pro? Picture is from MegaSquirt

    LS Coil Wiring - Miata Turbo Forum - Boost cars, acquire cats.
    LS Coil Wiring - Miata Turbo Forum - Boost cars, acquire cats.668×312 6.5 KB

  2. There are 4 pins on the alternator plug, I’m not sure about B and C:
    A - not used
    B - alternator turn on - switched +12V through ignition or switched to ground?
    C - signal to control voltage, auxiliary output on EMU Pro, set as alternator output at 100Hz
    D - Battery +12V constant to supply the internal regulator I guess

    grafik
    grafik926×703 125 KB

Thanks in advance :slight_smile:

2

We run the LS style coil back to cyl head for ground and ref. Some coils we solder and pot, when doing so we push the 2 ground pins together and solder a single wire to them. No issues in all the years we have been doing this. There is also no need for a cap like the MS picture above.

With the 4 pin style alt, you realistically just need the Lamp, B, terminal to an incandescent bulb or IGN with proper resistor. The 2 pin hairpin style, thats a different story.

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