Ok.. So it not working then shouldn't have anything to do with the Alt. not charging. I read on a thread on this forum that the alt. required 12 volts across that to charge... I think. Which is why I was looking into it.

 

<p>I was wrong. Under 14 volts field should be equal to the 12v source. So you need to adjust the pot.</p><p>Hold on I'm figuring out which way to turn it.</p>

 

<p>Turn it clockwise until it starts charging.</p>

 

Ok, I will try again... But when it was showing 12+ volts, it still wasn't charging. LEt me go try it again and I will report back.

 

<p>Throw the battery on a charger and get it nice and full.</p><p>Then try again with a fully charged battery. Adjust the pot until its charging at 14.4 volts. Counter-clockwise=lower. Clockwise=higher</p>

 

Yea I have it so it is reading 11.87 right now. As high as it's going to go. And it isn't charging. My battery it pretty low at this point so I will put it back on the charger.

 

yeah, that suggests the alternator is not coming on.

 

Yea, I fully charged the battery... still not charging. So I will take the alternator off, take all three alts. that I have, get them tested. and go from there.

 

Well, all three of my alternators test as good. Both NB's and the NA. So back to the drawing board.

 

Well the moral of the story is don't let me solder without my glasses. I soldered it to 1Q instead of 1O. It works now. Thank you everyone for trying to help and sorry I wasted your time.

 

;p it happens.

 

Getting old sucks

 

I finally got a chance to test this on the bench. Works perfectly. Thanks Frank.

 

good job, thx for letting me know

 

I know this is a stupid question but I don't want to fry anything. Do I need a pull-up or a transistor isolation circuit for the Disable line or can I run a line straight from JS0 to the Disable pin on the Alt Ctrl board? If I need a pull-up, do I need a 5V or a 12V?

Thanks

 

no pullup needed, to stop charging, just ground the disable line.

 

Still have several of these. We used them to control the alternator on our NB EMS-4 product, so they can be used for just about anything that doesn't have onboard alternator control.

https://www.miataturbo.net/miata-par...9/#post1322298

 

Having a possible issue with the board. Figured someone might be able to help.

Its been working great for like 8 months. But just recently the alternator started skyrocket to like 16 volts when doing pulls.

Bad alternator? Bad board?

Is there a way to check?

 

Check the voltage output of the circuit. If it's pegged at 5 volts, bad regulator. If it's at 0 volts, the regulator is trying to shut down a runaway alternator and the alternator isn't listening.

 

I believe Frank's board takes it up to 12V, so if the output is 12V (or higher) during a voltage spike, there's a problem with the circuit. If it's 0V there's a problem with the alternator.