Board logo

alternator wiring
auzziejim - 14/10/06 at 06:03 PM

i have a nippon denso alternator from a daihatsu charade and having searched the archives i find out the alternator needs a feed through the battery light on the dash as well as an ignition live feed. however with my digidash2 how do i splice into the battery light as there is no wire for it

cheers

james


RazMan - 14/10/06 at 08:51 PM

I could be wrong so don't quote me on this ....

The Digidash has a voltage sensing warning light (only comes on when volts drop below a threshold) and therefore you will need to wire a separate filament bulb to the 'L' connection on the alternator. The other side of the bulb goes to a switched feed. This will give you the right conditions to excite the coils and start the alternator charging.


auzziejim - 14/10/06 at 09:14 PM

would that mean the bulb will be constantly lit?

any normal warning light will do i suppose with a feed from the ig +


RazMan - 14/10/06 at 09:50 PM

No, the bulb would only light when the alternator stops charging for any reason or when the engine is switched off. This is a requirement for alternators but the digidash has an led which does not give the right conditions to trigger charging.
It is a coincidence that I was having problems in this area but with my Evodash. It turns out that the Evodash emulates a filament bulb and therefore works in the normal way.

edit: Any bulb will do - it just needs to be a low wattage filament bulb. When it is fed from both sides (alternator and switched feed) the bulb is at zero voltage. When the alternator switches to earth, the bulb lights.
The Digidash will give a similar warning but it has to wait until the battery drops below around 12V which would also indicat that charging has failed.

[Edited on 14-10-06 by RazMan]