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Discussion Starter #1
Hi all... i'm a bit stuck...

I've got a new alternator with the inbuilt regulator... I've wired it up as per instructions.... However the dash light does not go off? with the car running I tested the voltage and I am getting 12.5V volts... not 14V plus which would indicate that the system is not charging?

Would the alternator need to be grounded with a separate wire? Not done

Any thoughts on what to check next?

The previous alternator worked fine with the external regulator. (which I still have as a back up)

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rev it up, blip the throttle a few times to a few thousand revs
sometimes it needs to be "excited" to kick in.
 

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Discussion Starter #3
Thanks, I've just pulled it out and put the original back in... all working fine... But I would prefer the new version with the built in regulator as there is less clutter!

I will have another go at the weekend... what would you rev it too? 2k? when I had it running I disconnected the positive on the battery and it stalled.. so defo not working.. Can it be tested off the car?

Thanks..


rev it up, blip the throttle a few times to a few thousand revs
sometimes it needs to be "excited" to kick in.
 

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blip the throttle to about 2000 (let it warm up a bit before revving on a cold engine!)...see if the red light goes out and the charge then jumps to over 14V

the ground is the alternator case so this needs clean contact with the engine
Your battery needs to be good....if it has a bad cell this could be a problem.

you can bench test some things at home, but really an output voltage test needs the alt secure in the vise, a 12v battery, some cables, a tester and something to spin it real fast....I don't think your normal black & decker will have enough speed.
 

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Discussion Starter #5 (Edited)
Ok.. thanks for the info.. the engine has not been run for a while so maybe I need to warm it up a bit more...

Assume if the original alternator works with the battery that would rule the battery out?

I will give it another go at the weekend..


blip the throttle to about 2000 (let it warm up a bit before revving on a cold engine!)...see if the red light goes out and the charge then jumps to over 14V

the ground is the alternator case so this needs clean contact with the engine
Your battery needs to be good....if it has a bad cell this could be a problem.

you can bench test some things at home, but really an output voltage test needs the alt secure in the vise, a 12v battery, some cables, a tester and something to spin it real fast....I don't think your normal black & decker will have enough speed.
 

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Rod, is the battery fully charged? If so, then there is going to be little demand on the alternator. To make the alternator do some work, switch on all the electrics, full head lights, heater blower, thats about the lot isnt it? Then as Don says increase the revs, 2k should be enough. If then its not doing what it should, I'd say its a duff unit, it could well be dead out the box.
 

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Discussion Starter #7
Thanks... yes fully charged... Some good points.. I've put the old unit back in for now.. should be able to spend a bit more time at the weekend swapping it back and seeing if I can try some of the suggestions. The "new" starter has sat in a box for 18 months...But still should that affect it? It may well be a duff unit!

Rod, is the battery fully charged? If so, then there is going to be little demand on the alternator. To make the alternator do some work, switch on all the electrics, full head lights, heater blower, thats about the lot isnt it? Then as Don says increase the revs, 2k should be enough. If then its not doing what it should, I'd say its a duff unit, it could well be dead out the box.
 

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you could run your battery down (leave the lights on a while)
that ought to "excite" the alternator (give it something to do!)
:)
 
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