MS2PnP NB1 alternator control not working what have I done wrong?
 

Hey guys,

Just fitted a MSpnp2 to an NB1, and the alternator is not charging, the documentation simply says that it controls the alternator but its not adjustable, as a result as far as I can see there is no info in the software for it and basically I dont know why it isnt working or even how it works.

Can someone please point me in the right direction?

Thanks,
Dann

it's a circuit built on the adapter board--it works independent of the CPU/software.

One thing to do is to make sure the tach output is turned on. If it is accidentally set to off, this will shut down alternator output.

Tacho output enabled: ON
Output on: TACHOUT
Speed: NORMAL

Any suggestions here?

Contact us directly at websales@diyautotune.com with an MSQ and data log of the charging issue.

Email sent, thankyou.

Back from the dead, so Nitrodann did you figure out a way to control the alternator with ms2pnp?

it's a built in feature.

To be specific, alternator control in the MSPNP Gen 2 is built into the one for '99-'00 Miatas, but is not a feature of the ones for NAs.

I have a 99 miata nb1 which i bought used. They told me when they installed the ecu it would not control the voltage. I am trying to make it work correctly so forgine the noob in me.

Exactly what ECU do you have there?

It is this one
https://cimg4.ibsrv.net/gimg/www.mia...25c68efd52.jpg

If i am not mistaken it is for 99-00 model.
And this is my car
https://cimg3.ibsrv.net/gimg/www.mia...1f6e1df22d.jpg

MSPNP2 MM9900 Battery Voltage too high
 

Was there ever a solution posted for this problem? I have the same issue with my MSPNP2 MM9900, for an NB1. Looks like the circuitry controls voltage level but any chance there is an adjustment?

Other work done to confirm it's the MS:

- Confirmed fully charged battery
- Confirmed voltage at battery (with a high quality multimeter) is matching Tuner Studio indicated battery voltage of 17 - 18+ vdc
- Removed and bench tested alternator at a parts store, confirming 15.1 vdc output
- Double checked block, chassis grounding with the MS and alternator connections
- Researched that the 2000 Mazda Miata uses the stock ECU for voltage regulation
- Researched the MSPNP2 has voltage regulation circuitry but it looks like only the MS3 allows tuner studio corrections

i bought the car used and they had swaped the NB alternator with an alternator from a NA miata that is self regulating. I went with ms3pro, so i did not bother with that at all.

Just to "put a bow" on this string for the next person looking for an explanation for crazy alternator/battery voltage after installing the MSPNP2 MM9900..... My voltage was reading 17=20vdc after the new install, which blew headlight filaments and shut off the radio due to over voltage. The problem was indeed with the MS, which was repaired under warranty by DIYAutoTune. They replaced component U1, which fixed alternator voltage regulation. I now have voltage readings of 13.5-13.7, verified with a quality multimeter at the battery.