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post #1 of 10 (permalink) Old 07-15-2018, 01:52 PM Thread Starter
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91 Spider Alternator issues

I have intermittent Alternator issue w/ 91 Spider. I Replaced the alternator but still happens. Alternator wont start to work ( charge) until car runs several minutes > 2000 rpm. After that, it will charge fine even at idle. if you turn off engine and restart just moments later, it does the same thing !
Where does teh green ,ground wire off the alternator terminate ? I see it goes to a terminal block on fender well then it goes through the fire wall. Should it be grounded to chassis ? It reads open to ground.
Is there another relay or sensing device that activates after a sufficient drain/load on the battery ?
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post #2 of 10 (permalink) Old 07-15-2018, 02:10 PM
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Does the indicator light on the dash work? Does the dash light glow brightly while the car is running those first several minutes > 2000 rpm? If not, that may be your issue. Some alternators need to receive voltage through the indicator light to know that the key has been turned on and that they should begin charging.

Jay Mackro
San Juan Capistrano, CA

'65 Guilia Sprint GT
'67 Duetto
'91 164L
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post #3 of 10 (permalink) Old 07-15-2018, 02:31 PM Thread Starter
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hmmm...it does not come on when you first turn the key and all the other indicator lights come on.
I have seen it flicker a few times, but the voltmeter seems to be working ( and shows drop in volts when you turn on the headlights or blower).
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post #4 of 10 (permalink) Old 07-15-2018, 02:31 PM
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The green wire runs from that terminal block on the fender through the alternator warning bulb on the dash to to the +12 output of fuse 8. It should not be grounded. It serves as the voltage sense & kickover for the alternator.

Fuse 8 needs to be good, and you need to have the correct 1.2W bulb in the alternator warning location for the system to work right.

Tom

1963 Giulia Spider (1750 engine)
1974 GTV
1991 Spider
Former: 1987 Milano Gold
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post #5 of 10 (permalink) Old 07-15-2018, 02:34 PM
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Quote:
Originally Posted by mwtsbt View Post
hmmm...it does not come on when you first turn the key and all the other indicator lights come on.
I have seen it flicker a few times, but the voltmeter seems to be working ( and shows drop in volts when you turn on the headlights or blower).
It should come on when you first turn the key, so something isn't right.

Tom

1963 Giulia Spider (1750 engine)
1974 GTV
1991 Spider
Former: 1987 Milano Gold
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post #6 of 10 (permalink) Old 07-15-2018, 02:55 PM Thread Starter
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that makes sense...the operation is intermittent and it acted like it was waiting for some other relay to close before charging started. Ive seen the bulb flicker so hopefully its just loose in socket and cant complete the circuit.
Next step is figuring out how to access display.
Thanks...
Mike
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post #7 of 10 (permalink) Old 07-15-2018, 03:16 PM
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Has the indicator bulb been changed? IIRC that bulb has to be a specific wattage (which I don't remember...) or the excitation circuit doesn't work right.

- - Eric
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~ 1984 Spider Veloce ~
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post #8 of 10 (permalink) Old 07-15-2018, 03:28 PM
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Quote:
Originally Posted by Gubi
The green wire runs from that terminal block on the fender through the alternator warning bulb on the dash to to the +12 output of fuse 8. It should not be grounded. It serves as the voltage sense & kickover for the alternator. Fuse 8 needs to be good, and you need to have the correct 1.2W bulb in the alternator warning location for the system to work right.
Right. The fact that the old and new alternator behaved the same way suggests to me that the indicator circuit could be the issue. Might be as simple as a loose socket that makes an intermittent connection with the bulb.

Jay Mackro
San Juan Capistrano, CA

'65 Guilia Sprint GT
'67 Duetto
'91 164L
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post #9 of 10 (permalink) Old 07-15-2018, 03:55 PM
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Quote:
Originally Posted by mwtsbt View Post
that makes sense...the operation is intermittent and it acted like it was waiting for some other relay to close before charging started. Ive seen the bulb flicker so hopefully its just loose in socket and cant complete the circuit.
Next step is figuring out how to access display.
Thanks...
Mike
It's not too tough. See the first three posts in this thread. Hardest part is getting the trim ring back in place along the bottom.

https://www.alfabb.com/bb/forums/spi...4-spiders.html

The bulb should be Sylvania 2721 1.2W. If you're going in there I'd replace the bulb regardless.

Tom

1963 Giulia Spider (1750 engine)
1974 GTV
1991 Spider
Former: 1987 Milano Gold
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post #10 of 10 (permalink) Old 07-15-2018, 05:40 PM Thread Starter
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Awesome guys, thanks a lot, on my way to auto parts store tomorrow. Are all the lights the same? Might as well change them all while I am in there. Car been sitting for 7 years....ugh!

I got it running but still needs a lot of TLC!
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