mystery current drain .7 amp
#1
mystery current drain .7 amp
1966 GT convertible, 75,000 original miles, totally rotisserie restored 2004-2008. All new or NOS components. Has about 700 total miles on restoration. Charging and all instrument circuits worked fine for 6+ years. Last 2 have been problematic.
I have a current drain of approx. .7 amps. It started by killing two batteries over 2 years, then caused some glitches in my Rally Pac and now an inoperative ammeter. I have tested the fuses by pulling all of them and reading the draw on those circuits. NADA. Tried reading draw off solenoid connections. NADA. Have not tried the alternator connections or regulator connections. It has been suggested I could have a diode bleeding. The charging system works well, pushing over 14V back into my battery, but unless I disconnect the battery + the drain will take it all the way down (I don't drive or start it very often). I'd like to NOT have to remove the number/date coded alternator to have it bench tested at some facility or shop.
IS THERE A WAY FOR ME TO TEST THE ALTERNATOR AND/OR REGULATOR CIRCUITS FOR CURRENT DRAIN WITH THEM BOTH ON THE CAR. IN MY GARAGE. WITH TYPICAL MULTI-METER. YOU GET THE IDEA.
I have a current drain of approx. .7 amps. It started by killing two batteries over 2 years, then caused some glitches in my Rally Pac and now an inoperative ammeter. I have tested the fuses by pulling all of them and reading the draw on those circuits. NADA. Tried reading draw off solenoid connections. NADA. Have not tried the alternator connections or regulator connections. It has been suggested I could have a diode bleeding. The charging system works well, pushing over 14V back into my battery, but unless I disconnect the battery + the drain will take it all the way down (I don't drive or start it very often). I'd like to NOT have to remove the number/date coded alternator to have it bench tested at some facility or shop.
IS THERE A WAY FOR ME TO TEST THE ALTERNATOR AND/OR REGULATOR CIRCUITS FOR CURRENT DRAIN WITH THEM BOTH ON THE CAR. IN MY GARAGE. WITH TYPICAL MULTI-METER. YOU GET THE IDEA.
Last edited by DALLAS916; 10-19-2018 at 02:39 PM.
#2
1966 GT convertible, 75,000 original miles, totally rotisserie restored 2004-2008. All new or NOS components. Has about 700 total miles on restoration. Charging and all instrument circuits worked fine for 6+ years. Last 2 have been problematic.
I have a current drain of approx. .7 amps. It started by killing two batteries over 2 years, then caused some glitches in my Rally Pac and now an inoperative ammeter. I have tested the fuses by pulling all of them and reading the draw on those circuits. NADA. Tried reading draw off solenoid connections. NADA. Have not tried the alternator connections or regulator connections. It has been suggested I could have a diode bleeding. The charging system works well, pushing over 14V back into my battery, but unless I disconnect the battery + the drain will take it all the way down (I don't drive or start it very often). I'd like to NOT have to remove the number/date coded alternator to have it bench tested at some facility or shop.
IS THERE A WAY FOR ME TO TEST THE ALTERNATOR AND/OR REGULATOR CIRCUITS FOR CURRENT DRAIN WITH THEM BOTH ON THE CAR. IN MY GARAGE. WITH TYPICAL MULTI-METER. YOU GET THE IDEA.
I have a current drain of approx. .7 amps. It started by killing two batteries over 2 years, then caused some glitches in my Rally Pac and now an inoperative ammeter. I have tested the fuses by pulling all of them and reading the draw on those circuits. NADA. Tried reading draw off solenoid connections. NADA. Have not tried the alternator connections or regulator connections. It has been suggested I could have a diode bleeding. The charging system works well, pushing over 14V back into my battery, but unless I disconnect the battery + the drain will take it all the way down (I don't drive or start it very often). I'd like to NOT have to remove the number/date coded alternator to have it bench tested at some facility or shop.
IS THERE A WAY FOR ME TO TEST THE ALTERNATOR AND/OR REGULATOR CIRCUITS FOR CURRENT DRAIN WITH THEM BOTH ON THE CAR. IN MY GARAGE. WITH TYPICAL MULTI-METER. YOU GET THE IDEA.
#4
#5
Of course! But first, how do you know the drain is 0.7 amp? With the engine shut down, key OFF, the alternator to battery main feed wire must have no current flow through it. If there is, it's going backwards, from the battery, through at least one bad diode, to ground. Connect a DC ammeter in the battery + connection, that is, remove the + battery terminal (cable), connect an ammeter between the cable terminal and the battery post: if current is flowing, BAD ALTERNATOR. imp
#6
You use the AMP Meter between the - battery terminal, and the - battery cable, with the
car off, keys out of the ignition.
THEN you pull fuses to see when the AMP load either goes down, or disappears.
Then you pull the + lead off the Alternator, check for same results.
car off, keys out of the ignition.
THEN you pull fuses to see when the AMP load either goes down, or disappears.
Then you pull the + lead off the Alternator, check for same results.
#7
You use the AMP Meter between the - battery terminal, and the - battery cable, with the
car off, keys out of the ignition.
THEN you pull fuses to see when the AMP load either goes down, or disappears.
Then you pull the + lead off the Alternator, check for same results.
car off, keys out of the ignition.
THEN you pull fuses to see when the AMP load either goes down, or disappears.
Then you pull the + lead off the Alternator, check for same results.
Last edited by DALLAS916; 10-21-2018 at 11:05 PM.
#8
.68 is a lot of current. if a standard car battery can supply 60 Amp hrs that means if a load of 60A was applied it would be dead in 1 hr. in this case a load of 0.68Ah is being applied that battery would be totally dead in 88Hrs or 3.5 days.
.68A is enough to make heat.
Things that would use .68A would include: Lights like map / roof, and trunk lights, dash and glove box. are any of these running? check at night. Radio / cd head units, Amps, Sub woolfer, GPS Trackers, or any other goofy aftermarket crap. Fuel pumps, fans things of this nature???
Ignition systems and stock things others than lights typically wont draw that much current...
does any of this ring a bell or give you any ideas?
.68A is enough to make heat.
Things that would use .68A would include: Lights like map / roof, and trunk lights, dash and glove box. are any of these running? check at night. Radio / cd head units, Amps, Sub woolfer, GPS Trackers, or any other goofy aftermarket crap. Fuel pumps, fans things of this nature???
Ignition systems and stock things others than lights typically wont draw that much current...
does any of this ring a bell or give you any ideas?
#9
DO you have a single wire alternator? If yes probably a bad diode. If no, either a bad diode or the mechanical regulator is not opening the field circuit when the engine is off. Lift the alternator wire off the starter solenoid. battery side post and see if the draw goes to 0. If yes the alt or regulator are suspect. If no then you have a short or bad component, however removing all of the fuses and still having a draw sort of points to the alternator.
#10
DO you have a single wire alternator? If yes probably a bad diode. If no, either a bad diode or the mechanical regulator is not opening the field circuit when the engine is off. Lift the alternator wire off the starter solenoid. battery side post and see if the draw goes to 0. If yes the alt or regulator are suspect. If no then you have a short or bad component, however removing all of the fuses and still having a draw sort of points to the alternator.
Last edited by DALLAS916; 10-22-2018 at 04:09 PM.