Dead Eldorado clock fixed
#1
Dead Eldorado clock fixed
My 78 Eldo has a bad clock. I was fortunate enough a few weeks ago to find a 77 Eldo, and for $300 got to remove whatever interior parts I wanted. I took the entire dash, all the harnesses and connectors, the vacuum lines, all the little goodies bolted to the firewall and sides of the underdash area, etc.
Just my luck, the clock in the 77 was dead as well. I took it apart, it looked ok, no rust, no obvious overheating, so I blew it out, soaked it in 99.3% isopropyl alcohol for a minute, blew it dry and applied 12 volts. Nothing - no gears moving, nothing. I gently started nudging gears with a dental pick and it started moving and keeping time.
Thoroughly pleased with myself I put it back together and applied 12 volts again. Nothing. Same routine - poked at any one of the gears, clock started. Turned off my bench power supply, turned it back on, no clock movement. So much for being smug - the universe does not like it.
Took a quick look at the little circuit board inside - noticed a 100mfd 16 volt electrolytic. Soldered a new one across the terminals, turned on the power supply and bingo - clock worked fine. Did that a half dozen times, all is well, reassembled the clock, and it works. Turned the power on and off a batch of times, no problem, and then left it running. It has not lost or gained time for the last 6 hours.
Apparently the capacitor charges at power on and provides the extra boost in current required for the motor to overcome its inertial load to start from a dead stop. After 40 years the original cap must have dried out to the point of not having the capacity to hold a charge, and replacing it solved the problem.
I have a butt load of these capacitors so if anyone wants one for their clock just shoot me over your name and address and I will mail you one at no charge.
Art
Just my luck, the clock in the 77 was dead as well. I took it apart, it looked ok, no rust, no obvious overheating, so I blew it out, soaked it in 99.3% isopropyl alcohol for a minute, blew it dry and applied 12 volts. Nothing - no gears moving, nothing. I gently started nudging gears with a dental pick and it started moving and keeping time.
Thoroughly pleased with myself I put it back together and applied 12 volts again. Nothing. Same routine - poked at any one of the gears, clock started. Turned off my bench power supply, turned it back on, no clock movement. So much for being smug - the universe does not like it.
Took a quick look at the little circuit board inside - noticed a 100mfd 16 volt electrolytic. Soldered a new one across the terminals, turned on the power supply and bingo - clock worked fine. Did that a half dozen times, all is well, reassembled the clock, and it works. Turned the power on and off a batch of times, no problem, and then left it running. It has not lost or gained time for the last 6 hours.
Apparently the capacitor charges at power on and provides the extra boost in current required for the motor to overcome its inertial load to start from a dead stop. After 40 years the original cap must have dried out to the point of not having the capacity to hold a charge, and replacing it solved the problem.
I have a butt load of these capacitors so if anyone wants one for their clock just shoot me over your name and address and I will mail you one at no charge.
Art
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