Author Topic: 1941 Cadillac Clock  (Read 224 times)

Offline C Gorgas

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1941 Cadillac Clock
« on: August 12, 2017, 10:13:17 AM »
The 1941 Cadillac clock has been rebuilt using quartz mechanism to make it run. It keeps very good time until I start the engine and then takes about 3 minutes or less time to rotate one complete hour. There is apparently some interference involving the engine running. I am at a loss. I have had the clock on the work bench using a battery charger and it works just fine as well. Is there something I might place in the hot side of the line that would counter the interference? Much like what one puts in the line to negate radio interference. Chet 25441   

Offline Bobby B

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Re: 1941 Cadillac Clock
« Reply #1 on: August 12, 2017, 02:21:24 PM »
Chet,
 What's the voltage at the clock source with the car running, and the car dormant? Did the quartz movement specify that positive and negative have to be adhered to?  Can the leads be swapped? If it runs on the bench, it should run in your car. Something isn't hooked up correctly.  Time Flies when you're having Fun.... ;D
                                                        Bobby

1947 Cadillac Series 62 Convertible Coupe
1968 Mustang Convertible
1973 Mustang Convertible
1969 Jaguar E-Type Roadster
1971 Datsun 240Z
1979 H-D FLH

Offline Bob Schuman

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Re: 1941 Cadillac Clock
« Reply #2 on: August 12, 2017, 02:53:39 PM »
Chet,

I had a similar problem with a quartz conversion clock in a 1940 LaSalle. It would keep perfect time, but sometimes after starting the engine it would lose about five minutes, then keep time but five minutes late. The clock had been converted by John Wolf Co. of Willoughby, Ohio. John provided a capacitor that I connected from the clock power terminal to ground, no further problem. I don't know enough about electronics to explain further, so I suggest you talk to whoever converted your clock for help. That car was 12 volts positive ground.  Wolf Co. converted the clock for my present 41, a six volt positive ground car, and it has not needed the capacitor to make it run properly.

Bob Schuman
Bob Schuman, CLC#254
1941 6019S
1949 6237X
1951 6137
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1948 Olds 98 Custom

Online bcroe

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1941 Cadillac Clock
« Reply #3 on: August 12, 2017, 04:14:21 PM »
Given that your clock only has 2 terminals (not including a pilot
light), there isn't any doubt the problem is with the power
source.  Of course the clock should have continuous power
independent of ignition.  I have seen similar problems with a
factory tach. 

Seems like there are 2 possibilities.  One is, starting the car causes
such a power disruption, it throws off the clock. 

The other is, running the generator system is causing noise pulses
to be fed into the clock power.  A scope would reveal what is happening. 

You could try running the lock leads as directly to the battery as possible,
not sharing any wiring with other (potentially noisy) circuits.  The other
method is add a filter at the clock power input, first guess is around a
1000 ufd cap, carefully observing polarity.  More extensive filtering
could be needed, esp if there is a problem with voltage dropout cranking. 
good luck, Bruce Roe

Offline C Gorgas

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Re: 1941 Cadillac Clock
« Reply #4 on: August 12, 2017, 06:46:22 PM »
I really appreciate the comments. I will try what you suggest Bruce and see what happens. The whole thing is strange to me. Chet 25441

Offline Barry M Wheeler #2189

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Re: 1941 Cadillac Clock
« Reply #5 on: August 13, 2017, 07:57:02 AM »
I have only scanned the replies, but why are you "hooking up" the quartz clock to the car? All the quartz motors I know of run on a AA battery until it runs down. No "connection" needed. The light should be part of the under dash wiring and have nothing to do with the clock portion mechanism.
Barry M. Wheeler #2189
1981 Cadillac Seville
1979 Cadillac Fleetwood Brougham
2016 Cadillac ATS

Offline C Gorgas

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Re: 1941 Cadillac Clock
« Reply #6 on: August 13, 2017, 12:00:36 PM »
I'm not hooking up a "quartz" clock as such. Maybe I did not describe it correctly. The movement inside the clock runs like a quartz clock but requires electricity from the car and in this instance 12 volts. Hope this clarifies somewhat. Chet

Offline 35-709

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Re: 1941 Cadillac Clock
« Reply #7 on: August 13, 2017, 01:16:06 PM »
And the car has been converted to 12 volts negative ground?
1935 Cadillac Sedan resto-mod "Big Red"
1973 Cadillac Caribou - Sold
1950 Jaguar Mark V Saloon resto-mod

Offline C Gorgas

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Re: 1941 Cadillac Clock
« Reply #8 on: August 13, 2017, 06:45:54 PM »
No. it is 6 volt and I have an inverter/converter. Chet

Offline Paul Phillips

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Re: 1941 Cadillac Clock
« Reply #9 on: August 13, 2017, 08:11:44 PM »
Probably this is not much different than the radio interference issues from the ignition. A large value capacitor (1000 uf) will help whatever power supply in your converted clock with general voltage fluctuations. If your problem is from higher frequency noise, you need a bypass cap on the power feed to the clock - something like 0.01uf to 0.1uf. Best plan is to do both the 1000uf and a .01uf bypass in parallel.

Paul
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1941 60 Special (6019S)
1949 60 Special (6069X)