Alternator Control. Dead nailed. MS3 / MS3-Pro / MSPNP-Pro
I spoke to the developer, no reason it shouldn't be working, and it seems we have more than a few running it succesfully.
Should just need a generic pwm out, 5v pull-up to the alt field out.
Should just need a generic pwm out, 5v pull-up to the alt field out.
My 1k resistor was probably just too much for the pull-up, and should have been like 460ohms. Just by the time I had to desolder the resistor from the proto area and all, I just installed Frank's board since it was already apart.
Megasquirt MSEXTRA / MS3EFI • MS3 1.3.2 source code released (View topic)
I attempted this yesterday. I haven't put it together because I ran out of time.
Does this look correct? It is from the 5v pad on the underside of the expander board through a 1k ohm 1/4 watt resistor to pin #27 (VVT).
Does this look correct? It is from the 5v pad on the underside of the expander board through a 1k ohm 1/4 watt resistor to pin #27 (VVT).
Well, I squashed a few other bugs unrelated to the alternator control and got my car running again tonight.
Unfortunately though my battery voltage isn't increasing. I installed a brand new AGM battery since I fear that my old one was toast and partially contributing to my problems and that battery was installed at 11.2v indicated from the wire that normally provides 12v to the MAF.
After several minutes the voltage increased to 11.4 volts but it never went up from there. It never dropped below 11.4 volts after probably 20 minutes of running so the battery IS being charged to some degree or else I imagine it would have died long before that and certainly the voltage wouldn't have gone UP.
For the record, it is an 01. The position 3M (labeled as Generator Field Control) was wired to the VVT out with a 5v pull up.

What should be my next step in troubleshooting?
Unfortunately though my battery voltage isn't increasing. I installed a brand new AGM battery since I fear that my old one was toast and partially contributing to my problems and that battery was installed at 11.2v indicated from the wire that normally provides 12v to the MAF.
After several minutes the voltage increased to 11.4 volts but it never went up from there. It never dropped below 11.4 volts after probably 20 minutes of running so the battery IS being charged to some degree or else I imagine it would have died long before that and certainly the voltage wouldn't have gone UP.
For the record, it is an 01. The position 3M (labeled as Generator Field Control) was wired to the VVT out with a 5v pull up.

What should be my next step in troubleshooting?
Last edited by Chiburbian; Jul 24, 2014 at 11:34 PM.
what makes you think PK3 is VCC?
VCC is H5. (it's actually labeled as such)

As far as I'm aware PK3 goes no where, so you're not adding a 5v pull up.
Move your wire to the correct place: H5
VCC is H5. (it's actually labeled as such)

As far as I'm aware PK3 goes no where, so you're not adding a 5v pull up.
Move your wire to the correct place: H5
Fixed and alternator control is working... Kinda.
While cruising I am at 13.9v for some reason. And a/c does bork my voltage at least initially but that could be because it drops rpm so fast. I will do more research this week end.
While cruising I am at 13.9v for some reason. And a/c does bork my voltage at least initially but that could be because it drops rpm so fast. I will do more research this week end.
I've been running the new code for a few weeks now and it works flawlessly for me so far. It's a bit weird at night, when you floor it and the lights dim a little, but that is a sacrifice I'm willing to make for some additional hp.
Thanks to the developers!
Thanks to the developers!
Thread Starter
Joined: Jul 2006
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From: atlanta-ish
The alternator cut off vs TPS can be disabled by setting the cut off point at 101% throttle position. It was a feature requested by some autocrossers where a couple of thou's might mean a lot.
Trying to get this running as we speak. I have it on the Stim, no change to the actual system voltage has any reaction to the alt control duty/freq.
BUT voltage on the output drops from ~7v to 0v at 15.1v--so looks like it's working. But the tune shows my target voltage is 14.0 at this instance.
BUT voltage on the output drops from ~7v to 0v at 15.1v--so looks like it's working. But the tune shows my target voltage is 14.0 at this instance.
Thread Starter
Joined: Jul 2006
Posts: 12,659
Total Cats: 134
From: atlanta-ish
Not that I see. I asked Ken & James to have a look.
Have you tried using a different PWM output?
Have you tried using a different PWM output?








