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Hello all, been a while since ive posted, always lurking though finding solutions on here for problems i cant solve.
1974 Spider, spica.

Was having a non start non charging issue, the battery was fairly new so i figured it was the alternator. Have a few other alts around so tried those but they just werent getting the voltage over 11-12, revving could reach close to 13v. however after running it for a bit and going to restart it wouldnt start. nothing no clicking or anything. Also tried a few regulators and an alt with an internal regulator.

Came to a conclusion the battery need replacing, so did that today started up right away so one issue was the battery.

Checked for parasitic drain, took fuses out one by one but still had a drain of about 2amps.

unplugged the regulator and the draw went away, this happens with the three regulators i have. was thinking ill try re installing the alt with the internal reg. The previous owner really did a number on the electrical and bodywork on this car :(

I guess my questions are, are all my regulators bad? how can i test them if i can? Theres a green wire that comes out the plug to the regulator and joins to a green wire that goes through the fire wall. my book says it goes to a 8 way connector. where might i find that connector? and does it go anywhere else from there? was thinking it might go to the gen light on the tach?

PO installed alarm, also top left red warning light had been coming on n off last week after a longer drive. supposed to be fuel pressure i believe but who knows what the PO did pehaps its the alt light. it would come on at higher revs and when id up shift and gently apply throttle it would go out so idk maybe its still the fuel pressure.

I do have a few other issues such as fuel and oil gauges but ill make a new thread for those, thanks for any help, Julian.
 

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2 amps! Wow... that is more of a shark gnawing on your leg.
 

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I would go with a later type alternator and get rid of the regulator. It is just something else to go wrong.
 

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Discussion Starter #4
Yea will be putting the alt with internal regulator on tommorow afternoon and see how that goes with the newer battery.

Does anyone know the function of the green wire? The alt with the reg has the red power wire and the green from the D+
 

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it is wired to the red alternator warning lamp
 

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The starter solenoid pulls much more than 2 amps. It sounds like the Alternator field circuit to me. It should go away when the alternator and regulator are disconnected.
 

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Thanks for the replies, will be getting at it again this afternoon. has been sitting overnight so will see how the battery is and will most likely put the alt with built in reg in later today. also i cleaned the connections at the starter the other day but i will b putting in another oil pressure sender as well today so will check those out again and check the other end of the wires as well. The generator light on the tach doesnt light up with key on so ill have to get to that and check the bulb as well. Thanks for the help.
 

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Discussion Starter #9
Got the draw figured out and it was to do with the regulator and or alternator, had some help from my dad we checked the starter and coil for any draws but they checked out good. Basically unplug the rugulator and the draw went away and also went away when the power wire to alternator was unplugged. Installed the alt i had with internal reg. At idle volts were around 12.7. they did not increase with higher rpm. let it sit over night and battery read still 12.7 when engine off. Took for a ride today came back and checked with engine running and read 13.4 still doesnt increase when revving, not sure if thats an issue but it is charging and the battery is holding the charge perfectly :) Gonna try installing oil pressure sender today if rain holds off, the gauge works so hopefully its just the sender. Thanks for the replies and help, much appreciated. Julian.
 

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parasitic drain problem:

1 alternator,

3 different regulators, (all probably still good)

problem persists?

Alternator most likely has a bad diode.

In theory the alternator output should remain constant once it "turns on" despite changes in revs due to the regulator.

The oil pressure senders seem to fail regularly, I seem to recall recommendations for a thin wrench.
 
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