Im sure this has been said a million times but... my alternator isnt charging. Bone stock 99 miata with gm ait, diyautotune ms3x, aem eugo x series, and an adapter harness built following trubokitty's instructions. Using a trubo kitty base map with almost nothing changed besides all my sensors and such. My alternator is not charging for some reason. I can start the car off a batter charger, and once running, the car can run off the alternator, but the battery dies once the car is off and its just a huge pain. I am going to buy a new multimeter because i think mine is shot, but it was reading 13.7 at the alternator which is low but it should be charging. Anyone got any tips or anything here, im really lost. Sorry if i sound dumb im somewhat jew to all of this. I can post my tune when I get home if it would help.

 

You installed the pullup resistor like the trubokitty guide shows?

Can you unplug the alt and put megasquirt into test mode? When you manually toggle the VVT pin in test mode you should get 0/5V on the grey/red wire. This should be from the 1K pullup on the ms3x card, alt charges with 5V, no charge with 0V.

Finally, you've got inverted "high speed feedback field control" alt control configured on VVT pin?

 

i did not build the ms3x so i assumed that it would be ready to go from diyautotune. I unplugged the alt and did the test and im getting 0v. Guess i'll take apart the ecu and see if that resistor is there?

 

Yep. Without the resistor the MS3x card isn't capable of providing voltage needed to make the thing charge.

 

damn, kinda silly that they wouldnt install that... cant even get my ms open bc they like loctited the damn screws.

 

Would u happen to know if there is any miata specific resistors relating to idle, because my iac valve isnt working at all as well

 

Yeah, because you followed half of the turbokitty directions if I had to guess. The idle valve is probably not getting 12V.

 

i didnt assemble my ms3x so i assumed i wouldnt need to open it. Settle down. Thanks for the help anyhow.