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Discussion Starter · #1 ·
Hi,

I have an NB with an aftermarket ECU that doesn't regulate the alternator. So, I bought an external regulator. That failed twice on me, so I decided to fit an NA 1.8 alternator. This works OK, I get 14,4 Volt. But not directly after startup. When I start the engine and let it idle, it doesn't charge. It only gives batter voltage, on the gauge / in Tuner, 11,8 volt. After I blip the throttle once, the alternator 'wakes up' and voltage goes to 14,4. And stays there, also when idling again. You can actually see it in the headlights even witouth measuring, they become brighter and stay like that after the throttle blip. Is this normal for an NA 1.8 alternator?

Thanks,

Hugo
 

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Happily expanding the To Do list since 1997
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I don't really understand alternators but it sounds like it lacks the excitation current it needs to get it going. (The current which trickles through the "Charge" light in the dash.) Once it's got going normally the current reduces to the point the lamp doesn't glow. I read somewhere if the alt spins fast enough it can "self excite" and begin charging. That sounds like what you're seeing.
 

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Discussion Starter · #5 ·
Hmmm, you might be on to something there. I haven't hooked up the dash indicator light yet (couldn't find the correct wire). Of what you are saying is correct, hooking that up should help.
 

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Happily expanding the To Do list since 1997
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Right. That'll be it then. When you hook up the charge light it should just work normally, as the charge lamp current actually starts the alternator working.

In fact for reliability there's a resistor fitted in parallel with the lamp in the dash so that a blown bulb won't stop the alternator from working, as a trickle of current can still flow.
 

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Discussion Starter · #7 ·
Now all I need is to find the grey wire under the dash, that comes from the alternator, to hook up to the dash light wire which I did find. Any guess where to start on a 1998 NB?
 
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