Current drain

[algj]

I have converted my 63 3.8L e-type to negative ground and alternator. Charges quite nicely, but I seem to have a key-off current drain on the battery. It is low and slow as it takes days to bring it down to no start power. Last night I noticed that the voltage regulator (not the dash one) stayed warm thru the night, so I wonder if that is involved. I did the conversion to alternator using the jumper wire from yellow to green wires, now tucked behind the alt bracket. I know it charges while running as the ammeter (I haven't switched to an in-dash voltmeter yet) shows charging under load and an attached voltmeter showed about 14.5V while running. Anybody else witha problem like this (or at least an answer)? I have competely reworked the car with all new harnesses and all the accessories (exc the clock, of course) work.
Also, does anybody know the correct way to connect the ammeter wires when I take it out to replace with voltmeter? My inclination is to just connect the two brown wires to complete that charging curcuit, but I don't want to make a mistake and fry all the wiring as these are two very large guage unswitched hot wires.
Al
1963 3.8L S1 e-type

 

[Deleted member 8987]

What kind of alternator?
Usually you try to use on that does NOT use an external regulator.
Make and model of alternator and regulator might help figure it out.

 

[algj]

It was the kit from RetroAir. I believe it has an internal regulator, but comes with instructions for "bypassing" the original regulator, which, essentially involves connecting the yellow and green wires and shimming the arm of the third (right-most) regulator coil so it stays permanently closed. Otherwise, no other changes.
Al

 

[Deleted member 8987]

Oh, my. I suppose that will work....unless you've got a carbon path in the insulators, or corrosion.
With negative earth, Bosch, Lucas, can't recall all the others, internally regulated, one "hot" wire (or split from same source to two....but connected anyway inside the alternator), one to the idiot light.
My MK2 is Lucas alternator, set up like that. I had to go find a Lucas external generator-style regulator to put back in the hole. The wire terminals on the original Lucas regulator on a MK2 anyway are hidden under the fuse cover...if you're worried, stick some old properly coloured wires with terminals on and let them terminate where no one can see them.
I can't believe they'd have you shim out the contacts....what happens if, in spirited driving, that "shim" falls out?

If the original generator regulator is getting warm, that's the first clue. Current generates heat.
Something is passing to ground somewhere, either inside that regulator or on one of the feeds still attached to it.
Dave

 

[algj]

the shim is pretty stable in there, although you're right, if it slips, it quits charging. i'd be more than happy to take the external alternator out of the system if anybody has a way to do it. theoretically, could jump the leads and leave it as a "dummy" in its place.
al
also, any idea on whether i should jump the two leads to the ammeter when i convert to a voltmeter?

 

[twigworker]

If you disconnect the alternator does the drain, measured across the battery ground with the ignition off, go away?

If so, pull the alternator and test each diode in the rectifier pack individually. If you are uncertain about that, have an alternator shop do it in front of you.

My thought is that one of the diodes has been trashed and is "leaking" current.

Another clue might be that when you are running the engine at say two thousand RPM at night in the dark, the alternator warning light might appear to be out, but if you cup your hand over it you might see it glowing just a little. That is a dead give away for a bad diode.

Jack

 

[DrEntropy]

My thought is that one of the diodes has been trashed and is "leaking" current.

This is golden.