Alternator dosnt charge battery - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


MEGAsquirt A place to collectively sort out this megasquirt gizmo

Reply
 
 
 
LinkBack Thread Tools
Old 09-03-2010, 11:41 AM   #1
Junior Member
Thread Starter
iTrader: (1)
 
Join Date: Jan 2009
Location: Tennessee
Posts: 58
Total Cats: 0
Default Alternator dosnt charge battery

Im running a parallel install of ms2, the car runs fine just it will die once the battery is depleted. The battery light is on and also my tach isnt working if that has any correlation. I'm thinking that i might have a wire ran wrong but i never touched the alternator or tach wires going into the stock ecu.

99 1.8l miata with ms2
hbrew is offline   Reply With Quote
Old 09-03-2010, 12:14 PM   #2
Senior Member
iTrader: (1)
 
Join Date: Jun 2006
Location: Sweden
Posts: 1,391
Total Cats: 58
Default

How is the parallel hooked up?
I'm not sure if the Stock ECU want to see rpm before it starts to control the alternator. How you should share the sensors (cam and/or crank) can probably be found (scattered) in more than 100+ places on this forum.
http://www.google.se/search?q=share+...miataturbo.net
A lot of reading but there are Brains on here that can guide you (quickly) much better than I can (a lazy slob that went with DIYPNP ).
NiklasFalk is offline   Reply With Quote
Old 09-03-2010, 01:51 PM   #3
Junior Member
Thread Starter
iTrader: (1)
 
Join Date: Jan 2009
Location: Tennessee
Posts: 58
Total Cats: 0
Default

Currently i have it wired up like this sharing cam, crank, and ait sensors with stock ecu.
'99 OEM Connector Megasquirt DB37

3Y and 3W Injectors 1&3 DB34&35

3Z and 3X Injectors 2&4 DB33&32

3Q VICS DB4 (spr2)

3O IAC DB30

3M IAC12v to 12V

3P Fuel Pump (w/ immobilizer)

3N Fuel Pump (wo/ immobilizer) DB37

3I Clutch switch

3J Rear O2

3G IGN 1, 4 DB36

3H IGN 2, 3 DB31

3E TPS DB22

3F Sensor Gnd to MS GND

3A Gnd DB19,18,&17

3B Gnd DB7,8,& 9

3C Gnd

2K Tacho DB5 (spr3)

2I TPS Vref DB26

2J Crank DB24

2H Cam DB25

2F Knock

2E CLT DB21

2C Front O2 DB23 (not connected to stock harness, will go to wideband)

2B IAT DB20

1V Neutral

1Q Alt Warning light DB6 (spr4) "Still connected to stock ecu"

1O Alt Field DB27 "Still connected to stock ecu"

1R Cooling Fan DB3 (spr1)

1I AC Fan

1B 12v DC DB28

EBC DB29 (not connected to stock harness, will go to EBC)

Last edited by hbrew; 09-03-2010 at 04:17 PM.
hbrew is offline   Reply With Quote
Old 09-03-2010, 03:37 PM   #4
Supporting Vendor
iTrader: (10)
 
Reverant's Avatar
 
Join Date: Jun 2006
Location: Athens, Greece
Posts: 5,441
Total Cats: 198
Default

Can you connect through the OBD port and check if the stock ECU is seeing any RPMs?
Reverant is offline   Reply With Quote
Old 09-03-2010, 03:56 PM   #5
Ben
Supporting Vendor
iTrader: (33)
 
Ben's Avatar
 
Join Date: Jul 2006
Location: atlanta-ish
Posts: 12,689
Total Cats: 99
Default

Why is your alternator field wire hooked up to the MegaSquirt?
Ben is offline   Reply With Quote
Old 09-03-2010, 03:58 PM   #6
Ben
Supporting Vendor
iTrader: (33)
 
Ben's Avatar
 
Join Date: Jul 2006
Location: atlanta-ish
Posts: 12,689
Total Cats: 99
Default

Quote:
Originally Posted by Reverant View Post
Can you connect through the OBD port and check if the stock ECU is seeing any RPMs?
Mine wouldn't share nicely. I'd expect that you need to remove the pullup from one ECU or the other, and probably need to diode isolate the inputs in order to successfully share tach signal inputs. I put a trigger wheel on the crank instead, because I had one laying around. In retrospect, I think that it was the harder solution...
Ben is offline   Reply With Quote
Old 09-03-2010, 04:16 PM   #7
Junior Member
Thread Starter
iTrader: (1)
 
Join Date: Jan 2009
Location: Tennessee
Posts: 58
Total Cats: 0
Default

ok minus the alternator wiring from the above wiring configuration. the alt feild wire is still going to the stock ecu.
hbrew is offline   Reply With Quote
Old 09-06-2010, 04:29 PM   #8
Junior Member
Thread Starter
iTrader: (1)
 
Join Date: Jan 2009
Location: Tennessee
Posts: 58
Total Cats: 0
Default

Well i figured out why the alternator wasnt charging, the Ait wire coupler wasnt as secure as i thought it was. But now that the alternator is working the car bucks and miss fires alot at low rpm/throttle position. anyone know what could be causing that?
hbrew is offline   Reply With Quote
Old 09-06-2010, 05:34 PM   #9
Supporting Vendor
iTrader: (10)
 
Reverant's Avatar
 
Join Date: Jun 2006
Location: Athens, Greece
Posts: 5,441
Total Cats: 198
Default

You need to tune the MS.
Reverant is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Project Gemini - Turbo Civic on the Cheap Full_Tilt_Boogie Build Threads 59 12-15-2017 09:00 PM
Expected intake temps on the track? tazswing Race Prep 20 10-03-2015 12:04 PM
Back to Stock Part Out!! Turbo Parts, MS2 Enhanced 01-05, Suspension, and MOAR! StratoBlue1109 Miata parts for sale/trade 16 10-02-2015 10:39 AM
wiring wideband ground to battery terminal btabor ECUs and Tuning 10 09-28-2015 06:33 PM
Another Alternator thread ihiryu General Miata Chat 9 09-28-2015 11:22 AM


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 07:56 AM.