question regarding charging system

[haaken675]

Hey everyone,

I am finally getting the wiring wrapped up on my build and very much looking forward to the first start of my m52 turbo swap. I have a question regarding the blue wire that goes to the alternator to excite the coil to get it charging. I am not running the stock dash at all, and have opted for a raspberry pi dash setup since I am running megasquirt.

From my understanding, the blue wire coming out of the dash that also goes through the c101 is needed to make sure the alternator actually starts charging the car. Is it essentially a 12v wire, or am I missing something? Could I just hook it up to a switched/ignition 12v source, or do I need to do something special to it?

Thanks in advance, all the help making the car run sooner makes the wife happy as it's getting all the parts out of the house, lol...

[haaken675]

I think I found my own answer, but someone please correct me if I am wrong. being that the blue wire is the exciter wire, all it is doing is giving a 12v input to the alternator. From what I can gather, as long as I have a switched 12v input I should be good, so I am planning on wiring it to the same 12v circuit as my MS3x so that it only gets power when the ignition is on.

Any issues with doing this?

[haaken675]

I'm starting to think this forum is dying.

[me_john85]

I agree with you a 12 V switched wired should be fine. I don’t see why it wouldn’t.

[nando]

run it through a bulb (like the stock dash) so you get a light when the alternator isn't working. IIRC the alternator grounds the bulb until it starts generating power, and since 12v - 12v = 0v the light turns off once it's running.

[haaken675]

Thanks for the replies. I have an aftermarket volt gauge installed in my dash panel, so that should clue me in if it stops charging. I have a few LED's lying around I didn't use that I could wire in line if necessary though.