Alternator dosnt charge battery
#1
Junior Member
Thread Starter
iTrader: (1)
Join Date: Jan 2009
Location: Tennessee
Posts: 58
Total Cats: 0
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
99 1.8l miata with ms2
#2
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 ).
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 ).
#3
Junior Member
Thread Starter
iTrader: (1)
Join Date: Jan 2009
Location: Tennessee
Posts: 58
Total Cats: 0
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)
'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 03:17 PM.
#6
Supporting Vendor
iTrader: (33)
Join Date: Jul 2006
Location: atlanta-ish
Posts: 12,659
Total Cats: 134
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...
#8
Junior Member
Thread Starter
iTrader: (1)
Join Date: Jan 2009
Location: Tennessee
Posts: 58
Total Cats: 0
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?
Thread
Thread Starter
Forum
Replies
Last Post
StratoBlue1109
Miata parts for sale/trade
21
09-30-2018 01:09 PM