Analog clock puzzle

[Boris3]

Replaced the 6 button obc with an analog clock on the 91is a while back. Everything has been working fine and still seems to work fine when the engine is running but this past month I've noticed that the clock now loses time when the engine is off. A lot of time. Overnight it will lose several hours.

Checked a couple of things. Battery reading on the multimeter with ignition off on Friday afternoon was 12.36 volts, at idle 13.67. Battery read at 12.28 this morning after sitting Saturday and Sunday. Took the car to Autozone this afternoon for a battery test and their battery load tester said the battery was good. Surprising since it's a 5 year old battery (interstate)

Car starts fine, tach and other gauges all working fine.

Ideas? Clock going bad, wiring connector issue somewhere, or clock is a canary in the coal mine and battery is going and/or early stages of other issues?

[audiquattrot]

my clock loses time also, but not hrs overnight. more like minutes over the course of a couple wks.

[Boris3]

A few minutes over a week would be fine and probably normal.

The electrical puzzle for me is why does the clock seem to work fine when the car is running, but lose time dramatically when the car is off for more than a few hours?

Ideally I guess I'd need to monitor it every hour to see how the loss builds up, and for comparison run the car for several hours straight to see the time loss pattern and if it matches up to the overnight loss.

But that's pretty out there behavior even for an e30 owner, and especially for a minor electrical issue. Hoping for a solution/approach though that doesn't have me sitting and staring at the clock....

[Boris3]

Just to update it looks like the issue was the clock. Last week it finally just stopped. Light would still work and I could reset the time but nothing after that.

Pigtail checked out fine with power to the clock (thanks to ST1G for helpful advice here). I finally ended up opening the clock housing. Gears, board and connections looked fine. Reassembled it and everything now seems to working. Go figure...

[straight6pwr]

good thing, since you need a 12 hour clock to time your laps!

[Boris3]

Different car but hey 12 hour clock and enduros... good to go.