Alternator wiring

Hi guys,

I have a 1JZ-GTE (from a JZX100) with the stock Denso alternator. I'm running a Link FuryX, Link Razor PDM, and AiM MXS Strada dash. It's a complete rewire of my track car. I've been using this page as a guide to wire it up: http://wilbo666.pbworks.com/w/page/39441708/Toyota Alternators

Currently my wiring plan for the alternator is as follows:

L (Charge Warning Light). Grounded when error condition.

Wire to a digital input to be able to display on the dash when the alternator isn't charging.

IG (Ignition Switch)

Wire to PDM.

S (Battery Voltage Sense)

Wire to battery.

B (Battery)

Wire to battery via isolator.

I have some questions. Apologies if they're dumb.

1. Does the battery voltage sense really need to go all the way back to the positive terminal? Or is it enough to just be wired before the PDM? Perhaps I could just wire it to my isolator also?

2. How much current does the ignition switch pin draw? I'd like it to share an output with something else on the PDM if possible.

3. Would 20 AWG wire be okay for IG, S, and L?

4. Is it okay to wire the charge warning light into a digital input? I've read about backfeeding, but I'm not sure if this is something I need to worry about.

Thanks in advance for any help!

1- I've done both. And having a large 2/0 alt charging cable and all other cables also. Had hardly no voltage drop and I just loop the sense wire right onto the alt charging post.

2- Im not entirely sure but it shouldn't be much at all

3- I'd go 16-14ga

4- this I'm not sure but do hope to see this get resolve, keep us updated!

I ended up wiring IG to the PDM and S directly to the battery positive. I didn't wire up the light beause my ECU and PDMs already have their own battery voltage runtime values that they can react to. Works fine.

So you just used the IG in the pdm as a switch 12v?

Yup. I even forgot to set it up in the PDM. Alternator wasn't charging or doing anything. I switched that pin on with ignition in the PDM and everything worked fine.