Does anything bad actually happen if you don't connect the L Alternator Terminal?
 

I have one of SilverRotor's 3rd gen alternator, which works excellent BTW (shameless plug). My question is, does anything bad actually happen if I don't connect the L term directly to the gauge cluster?

Obviously my S term is getting 12v, but the L term isn't jacked into anything, and it doesn't seem to affect my gauge at all (still reads properly)?

Ummmmmmm dunno...

S terminal should be connected directly to the battery on an S4.
L-terminal goes to the gauge.... funny that your gauge still works....

If the S terminal isn't connected to the battery, the alt can discharge your car while it sits because the FD alt expects to see voltage when the ignition is off....

yeah... I'm good on the S term.. the L term is what I'm questioning :)

dunno.....

The S term determins if the alt charges or not, I know that.. BUT, what i don't know is if the L term is just for the gauge, or if there is some kind of diode bridge in the charging circuit that the L term is hooked up to....

I'd hook it up!!!!!!!!!

eh, the reason that I'm asking, is because I have a custom wiring harness... and I don't feel like pulling my gauge cluster out (again) if there's no reason to :)

It supplies ground when the alt is not running so that you can see if the belt has become disconnected or the alt has failed.

Nothing will happen without it hooked up... You just won't have any sort of warning on charge failure.

Yup, I have mine disconected. You just wont get that warning light if the belt breaks, or alt gets fried.