You might want to read this - there is more to these little clocks than most people realize:
Testing and Inspection
Regulation of the electric clock is accomplished automatically by resetting the time. If the clock is running fast, the action of turning the hands back to correct the time will automatically cause the clock to run slightly slower. If the clock is running slow, the action of turning the hands forward to correct the time will automatically cause the clock to run slightly faster (10 to 15 seconds day).
A lock-out feature prevents the clock regulator mechanism from being reset more than once per wind cycle, regardless of the number of times the time is reset. After the clock rewinds, if the time is then reset, automatic regulation will take place. If a clock varies over 10 minutes per day, it will never adjust properly and must be repaired or replaced.
WINDING CLOCK WHEN CONNECTING BATTERY OR CLOCK WIRING
The clock requires special attention when reconnecting a battery that has been disconnected for any reason, a clock that has been disconnected, or when replacing a blown clock fuse. It is very important that the initial wind be fully made. The procedure is as follows:
1. Make sure that all other instruments and lights are turned off.
2. Connect positive cable to battery.
3. Before connecting the negative cable, press the terminal to its post on the battery. Immediately afterward, strike the terminal against the battery post to see if there is a spark. If there is a spark, allow the clock to run down until it stops ticking, and repeat as above until there is no spark. Then immediately make the permanent connection before the clock can again run down. The clock will run down in approximately two minutes.
4. Reset clock after all connections have been made. The foregoing procedure should also be followed when reconnecting the clock after it has been disconnected, or if it has stopped because of a blown fuse. Be sure to disconnect battery before installing a new fuse.
TROUBLESHOOTING
If clock does not run, check for blown ``clock'' fuse. If fuse is blown, check for short in wiring. If fuse is not blown, check for open circuit.
With an electric clock, the most frequent cause of clock fuse blowing is voltage at the clock which will prevent a complete wind and allow clock contacts to remain closed. This may be caused by any of the following: discharged battery, corrosion on contact surface of battery terminals, loose connections at battery terminals, at junction block, at fuse clips, or at terminal connection of clock. Therefore, if in reconnecting battery or clock it is noted that the clock is not ticking, always check for blown fuse, or examine the circuits at the points indicated above to determine and correct the cause.
