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I have a 1981 C3 with a 2018 rebuild where the PO put in a 350/290. The firewall has a bunch of extra connectors just hanging there "dormant" (or at least hoped dormant). I have had the car for about 2 months and have a nagging current draw on the battery making it dead after 2-3 days of sitting in the garage (SC hot unattached garage mind you). I read somewhere that anything less than 100milliAmps is OK sleep current on a battery. I tested mine and it reads 0.13milliAmps.
Any suggestions? Is something "waking-up" when I'm not looking that draws more? Love any/all thoughts
No hadn't thought about load test - new battery (battery 1.5 months old). I could do that this weekend though - never know when a bad one comes off the assembly line.....
No hadn't thought about load test - new battery (battery 1.5 months old). I could do that this weekend though - never know when a bad one comes off the assembly line.....
Exactly, new doesn't guarantee it doesn't have a bad cell.
that amount in 3 days is curious.
it is higher than normal and should be fixed.
I am curious about "all the loose wires and whether
the computer is used.
need more info and pics.
I'll get a pic of the flat multi-pin connectors that are grouped high on the center firewall. My memory is that they are 8 to 12 pin flat connectors,....like three of them.
As for the charging system - YES - I am assuming it's doing what its supposed to do ONLY based on the fact that my voltage guage goes to between 13-14VDC AND the alternator was new part of the overall rebuild back in 2018 (the alternator is SHINY too ;-) ).
I would hook up your amp meter to the battery and start pulling fuses until it shows zero draw. Then you know what circuit the draw is coming from.
pat
The first rule of owning a classic car (or anything, today), shiny and new doesn't mean it works correctly. You could have a bad diode in your alternator.
Pull fuses until you find the circuit. If you pull them all and still have a draw, it is likely your alternator.
From: Loud, Raw and Dangerous 1968 327 4S in Southern California
Shouldn't the red plug of the meter be plugged into the "A" connector to read current? Update: Checked my meter and there is a switch position for ma/ua that uses the existing red connection shown. As Bikespace mentioned below there could be a blown protection fuse in the meter if the current draw was too high for that input.
Last edited by Redvette2; Jul 23, 2023 at 02:54 PM.
Reason: Updated info.
Just got a call from a friend who was relieved to find that it was his electric choke. Myself I couldn't tell that it is was my center rear compartment light always on even with the lid closed.
Shouldn't the red plug of the meter be plugged into the "A" connector to read current?
I wondered that too. That is correct for reading mA (milliamps). It indicates 0.13 milliamps, or 130 microamps. At 12 V, that's less than 2 milliwatts.
That's not what is causing the battery drain, though I'm willing to bet that the fuse inside that multi-meter is fried.
FWIW, I use one of these if I need to test the power draw of something. Much safer than the car's battery. Set a current limit, no blown fuses, or fires.
While you are troubleshooting, install a battery disconnect switch.
I just did that! :-)
So this is my present condition. I had challenges with charging the battery back up over the weekend. (my big professional Schumacher charger never progressed to "FULL" until after a messed with the connections 3-4 times - battery got hot which alarmed me) BUT battery is back in and cranked strong. Drove it Sunday and today and I disconnect the negative terminal switch each time I get out (pain...)
Last edited by RubbaBizkit; Jul 24, 2023 at 01:16 PM.
Reason: left out
Shouldn't the red plug of the meter be plugged into the "A" connector to read current? Update: Checked my meter and there is a switch position for ma/ua that uses the existing red connection shown. As Bikespace mentioned below there could be a blown protection fuse in the meter if the current draw was too high for that input.
Bugger current draw killin battery
