I drove my 72 coupe for two years and the clock kept perfect time. I think it is a repl. Clock because the second hand has a sweeping motion not a ticking motion. I assume that means it is a repl. Clock. Anyway all the sudden the clock would not keep time anymore it ran it just would not keep accurate time. I thought oh well time for a new clock I'll get around to it one day no big deal. I was cleaning the battery compartment so I had the battery out of the car for about a 1/2 hour. When I put the battery back in just out of habit I reset the clock, that was about six months ago and since then guess what the clock again is keeping perfect time. Yesterday I go out for a drive and notice the clock is way off again. Here we go again, so I disconnect the battery and wait about a 1/2 hour and then hook it back up and reset the clock. Now 24hrs have gone by and the clock is keeping good time again. In conclusion it appears that in my case taking power away from the clock fixes it for awhile anyway. So if you are having trouble with your repl. Clock try disconnecting your battery.

 

"Resetting" the clock might be whats making it keep better time. (Also the sweeping motion means its a quartz clock )

 

No. I reset if many times that never helped. It's from disconnecting the battery for some reaso.......weird.

 

even a broken clock is right twice per day

 

Taking power off doesn´t help a mechanical clock nor a quartz clock in keeping time.

If you adjust a mechanical clock by turning the pin, you are triggering its speed also!
If you turn it back, you will lower the speed of it. If you turn it forward, you will increase the speed. (There is a mechanical link from the pin to the timing spring adjustment)
This was done to auto-adjust the clock speed by the customer. You need to adjust it in smaller and smaller steps, until it keeps time perfect. So you have to check the time at least once a day.

 

zuendler, that's for a factory clock, not for a quartz conversion, which the OP has, as evidenced by the second hand making a sweeping motion, not a "ticking" motion.

 

you solution does not make sense. unless you have a intermittant ground issue when hitting a bump or something on your instrument cluster... the problem is not your main ground. if your car starts then the main frame ground passes hundreds of amps whereas your clock might take 10 milliamps. it is either a bad connection or a bad clock.

 

I offered no solution. I have no doubt that it is a bad clock. I'm merely stating to anybody that has a quartz clock that is running but not keeping good time try disconnecting the battery and hook it back up and it may help for whatever reason. I can tell you this much it helps mine. I have no bad grounds or anything like that I have a bad clock but if disconnecting the power every six months fixes it for another six months that's allot easier and cheaper then buying a clock. That's all i am trying to say.

 

yes your solution is to disconnect the clock and hook it back up again from the power source... could someone 'splain how and why this would work?

 

This is how urban myths get started.
Let's add to the myth. The quartz crystal needs to rest every couple of months from the intense vibrations it is subjected to when it's connected to power.....

 

Mine is set to 4:20 all day long!

 

Doesn't the car have to be parked with the nose pointed at magnetic North when you first connect it?
Or was it that it had to be parked going up hill at an angle so the clock was perfectly straight up and down?

 

But seriously
The quartz movement works on the crystal vibrating at a specific frequency when it's affected by the outside influence of the electrical feed.
The size and shape of the crystal determine the frequency it will vibrate very accurately when given an electrical feed "within a certain amount"

A quartz clock will go a little weird just before the battery dies when the power drops too low the freq. will drop and then it will quit completely.

My guess would be that the clock may have had a poor ground (or power) and was sinking it's ground somewhere else (through a lamp or something) and while receiving enough to run, not enough to get the crystal buzzing properly.

The ground on the clock may be dirty (loose, corroded, oxidized, etc) and the simple act of disconnecting / reconnecting the battery might create just enough of a jolt or "spark" (not literally) to "fix" the connection for awhile

The only other reasoning I'd guess at would be something in the clock that is worn/dragging a little and when it gets the jolt from a re-connection it takes a while to get back into that dragging position. again

Mooser