my test was always turning on headlights and a/c at the same time I was dropping bass through my 500 watt amp. :)

It will require hardware modifications and will require 2 output ports.

For clarity sake, on a 99-00 would that be ECU pin 1T for the field line, and 1O to read the voltage?

https://www.miataturbo.net/attachmen...ine=1402493058

Cool. That will regulate to within ~0.2 V from no load to full load, with very fast transient response. And if one wanted to have even more accuracy, put a PI loop on top of it. ;)

How are you wiring the alternator so it doesn't spike 14volts?

Confusing question is confusing.

The alternator is currently charging 18v. It's not good at all. I just installed the ms3.
It should be 1 wire will have a 12V feed and the other will be control (ms) but which one is which?

wtf?

I'd start by wiring it correctly, then tuning it correctly.

We are working on the wiring before we tune atm. The voltage is what's stopping us.

Well if you're using MS to control your voltage, and you haven't tuned it, how do you expect it to get correct in the first place? Are you using the 1.3.2 firmware with the "Miata" control method?

Everything is running properly. Fans, ac, idle. It's the voltage that were receiving out of the alternator is what's scary.

how are you controlling it?

I'm assuming it would be:

1O field out - spare PWM output.
1Q charge indicator - spare medium/high output (like inj e-f-g-h)

I'm also assuming that 1Q is optional if you don't want a low voltage indicator.

1T is a input/ground from the alt. to the OEM ECU to let it know the alternator isn't functioning (something to that matter), it is unused.

The Mazda diagram is kind of confusing. 99/00:
Alternator field is 1O
Alt sense is 1T

01/05:
field is D4
sense is E27
Where D is the 24 pin plug and E is the 31 pin plug

I appreciate it. Hoping this will help.

So I will be simply hooking the alternator field wire from 1O to the nitrous 1 pwm, using the exact settings posted in Ben's first post aside from changing miata to the renamed "high speed" setting, and changing the output to nitrous 1. Correct me if I'm wrong, otherwise I'll post the result. lol.

are you even using 1T, you'd hook it up like I suggested in teh post before yours, correct?

Moderators:
Should we move this over to the Megasquirt subforum?

PWM outputs supply ground, so me thinks you need to add a 12V pullup.

5V pullup, but otherwise correct.

No, wire it like my post.