Chasing a battery drain

[Max (SD)]

Last fall before putting the car away for the winter I had discovered a battery drain. The battery was removed and the car was stored in the back of the garage, and another car parked behind so it was not easy to get to and address the issue.

Well the weather is warming up and all the cars are ready for summer driving. Here is what I have,

1. When either door is open the interior does not go on, unless the motor is on

2. When I connect the positive lead to the battery I hear the top most round relay engage with a distinct click.

3. I disconnected the positive lead and used a voltmeter holding one point to the positive on battery and the other on the positive wire, and there is significant draw.

4. I reconnected the battery and went through the column of fuses to see which fuse was drawing power by holding the voltmeter on either end of each fuse, but none of fuses in the trunk had any draw.

Any suggestions?

[Vintage Racer]

It is difficult to diagnose an electrical problem on the internet. I do have some experience since I once owned a British car.

Are you sure the battery is good? You have one battery (and not two)?

Which relay is "clicking"? Is the relay good?

How many amps are escaping from the battery when you test it with the ignition off (the clock can draw when recharging)? It's a low amp reading?

I'd guess the draw is before the fuse box. I'd disconnect one wire at a time that doesn't go to the fuse box to find the drain.

[Max (SD)]

Battery is brand new Sonnenschein A512/40A

Just one battery, passenger side has been taken off and closed as front oil cooler hangs from the outside.

Not exactly sure to what the relay is attached to, will have to get back on that one.

132.0 m A escaping

[Vintage Racer]

Battery is brand new Sonnenschein A512/40A.

Max,
I bought two new batteries for my '73 car after the other(s) failed. I installed them, and the car started and ran well. Then the next weekend, the battery system didn't work. It was one new battery that lost a cell which then drained the other good one. They replaced it under warranty. Then a year later the same thing happened again to the other battery (this one spit out battery acid into the front inner pan- no fun cleaning this up). It was replaced under warranty.

If a starter solenoid (aka, relay) receives insufficient power from the battery, it will fail to start the motor and will produce a rapid clicking sound. The solenoid itself can fail and start clicking (don't ask me why). I am a shade-tree mechanic, at best.

Another thing. I keep my negative connection from the battery to the frame as clean as the inside of a Swiss watch. They can corrode naturally (esp. if the clock works). WD40 works well as it puts a film down after cleaning everything and does not interfer with the conduction of electricity.

[ejboyd5]

1) Try it with the fuses once again. This time remove each fuse completely to see which circuit has the drain.
2) If all fused circuits are negative, check the diode in the alternator which may be passing current.