Orange6

Hey folks, I'm attempting to help a friend with his corvette. I disconnected the battery and inserted a Fluke 177 dc amp meter in line with the battery connection. courtesy lamps, and under hood service lamps have been disconnected. When experiencing this drain the meter reads .1 amps, or 100 milliamps. I've taken every fuse out one at a time. The fuse blocks were passenger side dash, and the long narrow one with the heavier ratings by the PCM. When present, the drain is there regardless of removing all fuses in sequence. other things disconnected were the headlight actuators, and red lead to the alternator stud. the drain is still present regardless of what fuses or loads were disconnected. Here is the strange part, connecting and disconnecting the inline meter connection, it was discovered that we may are may not get a drain. During troubleshooting we were almost at the point of saving this work for another day because we could not get the drain to appear. After getting it appear we could not always get a repeatable fault, if the inline meter connection was removed. it seems like what ever it is not a fused load. the two wire alternator connection was not removed. any known likely causes. thanks you for your help.

NavAir

You could have a shorted diode in the alternator, although usually this drains more current than 0.1 A. Try disconnecting the alternator...

steve

Orange6

Thank you Steve, it escapes me if the molded two wire connection to the alternator is the diodes or the stud mounted red lead on the rear. the red lead was disconnected, not the more difficult to remove two wire connection was not disconnected.

NavAir

If you disconnected the red (stud) lead and still have the parasitic drain, it is not the alternator.

Steve

hcbph

Here's a tool that may be of use. Take a fuse out of the fuse block, plug it into the tool and the tool into the spot where the fuse was and see your reading. I know you said you pulled the fuses, how about the circuit breakers? You should have at least 4 of them in the fuse block alone. Then there's the addin block in the dash.

Orange6

That tool looks very helpful. We did the circuit breakers near the passenger side fuse block, where is the "addin" fuse block in the dash? This would make two fuse blocks in or around the dash, not counting the heavy rated fuse block in front of the PCM. Not Corvette smart, thanks for the help and advise.

Gene D

Voltage regulator in alternator could draw.
The plug to the alt should be removed. the signal wire goes to the regulator.
Not sure what year you are working on.
MY C4 has two banks of big fuses by the battery.

hcbph

Added fuse block noted in mine inside the dash around the DIC somewhere. I have not torn mine apart but as I understand it's in there somewhere.

knikula

disconnection of some circuits will cause them to re-initialize, example is the courtesy light timer.

ECM has a steady drain too....

what is the correct amount of drain for a stock '94?

remote entry has some current steady draw...if your car has that

my '84 manual says expected operation of the car is "some use every day".... to recover from the drain, I'd guess...

disconnecting the courtesy fuse on my car dropped the drain from 55mA to 22mA.
battery maintainers are likely the solution for occasionally run cars...

good topic...

hcbph

Another thing you can do is similar to what I did. I replaced the negative battery cable and added one to a battery cutoff then from the cutoff a new cable to the negative on the battery. Nice 250 amp Summit unit, quarter turn off the handle and the battery is disconnect or reconnected. I like it for winter storage, couple of seconds and the battery is disconnected.



Fits perfectly in the well under the drivers side headlight. Had to make one plate otherwise everything was a bolt in.

BlowerWorks

So what's wrong with the 100 ma draw ?