fd alternator wiring
 

hello! i need a help!
i use a fd 160 amp alternator in my rx8 ! but the oem rx8 charging system control voltage in pcm! now i upgrade the alternator to fd 160amp! and the wiring i think i need to mod! in the S and L wiring
1.terminal B to + battery
2,wire in plug connector (S) to fuse block (sense)
3.L that i dont know how .is supouse to go to charging ligth! but in my r8 i dont think that work! maybe i need a conversion adapter or external warning ligth?

look the picture ...i need to install custom ligth?

You need to find a switched (+) source to hook the L terminal to with a conventional incandescent light bulb in series. I would suggest you add the bulb somewhere in the cabin so you'll have something that will light up if there's a fault.

If you don't hook the L wire up, the alternator won't reliably produce power. The alternator uses this terminal to initially excite the field and start the whole electric generation process.

[QUOTE="JM1FD;11810533"]You need to find a switched (+) source to hook the L terminal to with a conventional incandescent light bulb in series. I would suggest you add the bulb somewhere in the cabin so you'll have something that will light up if there's a fault.

If you don't hook the L wire up, the alternator won't reliably produce power. The alternator uses this terminal to initially excite the field and start th
ok let me know I am wrong.
the L conector in alternator need some 12v consume some resistance to work. I cant hook in serie a a 150ohm resistance from 12v source to L conector in alt?

I think the problem of a bulb is if the bulb blown or broke.

Attachment 543979

or that

I would think that both setups would work, with the caveat that I can't say if 150 ohms is a good value or not.

If it were me, I'd measure a good bulb and then try to match the resistance as closely as possible if I wanted to go the resistor route.....but then you don't have a warning lamp if the alternator fails.

here my results
at 1,000rpm digital multimeter in trunk battery and microtech display. with fd alternator 160amp.
with rx8 alt 12.8vdc..
first results
1.volts from 12.8 rx8 alternator to 13.9 with fd in trunk battery
2.rpms up .500
3.the voltage no drop when electric fan go on
next step upgrade cable from alternator terminal to battery #2
here the wiring I made.

Why do you need a resistor on the "L" ?

Isn't the light just a warning? Could a straight 12v switched source work fine?

the idea of the resistor is simulate the resistance of the bulb.
i do with the bulb . because rx8 car control the regulator by pcm.
that is a pic of my results.