What could cause a slow clock?

[floete]

It's not that the clock in my '76 doesn't work, it's that it's either running slow or running intermittently. figuring the problem was with that particular clock, i bought another one, used, from a vendor here, who said he tested it, and this one does the same thing. crap. so, if it's not the clock, what else could it be ... and how can i fix it?

thanks!

[Howard M]

Have you been driving near the speed of light?

[chris 964]

Theory of Relativity - Technically its called "time dilation" the higher above sea level you are the faster clocks run. So are you below sea level?

Could be just bad luck with the 2nd clock

[sballard]

The clock in my '72 has a screw adjustment on the back side.

[regency]

floete: My clock runs slow too........I fixed mine by setting it about 4 mins ahead everytime I drive it.....I'm a pretty good mechanic.


Steve

73 911T MFI Coupe, Aubergine

[GH85Carrera]

Originally Posted by Howard M

Have you been driving near the speed of light?

That was my first thought as well.

[Drisump]

Originally Posted by Howard M

Have you been driving near the speed of light?

Thats what I was thinking....

[ossiblue]

I've had a similar problem with the clock in my 73, though not as pronounced as yours. It keeps perfect time but occasionally, I'll notice it's lost 5-10 minutes. This is very intermittent, like once every two to three months so I haven't really bothered to trouble shoot but I suspect something in the clock itself rather than the wiring. My guess is something is amiss in both clocks you have. The second, used clock, most likely was tested by the seller but unless it was run continuously for many hours the fault didn't show up. The only other possibility is the fuse which controls the circuit (as well as the dome lights and glove box light) may be corroded a bit and there is an intermittent loss/drop of voltage--something you wouldn't notice from the other items on the circuit.

[Joeaksa]

Have you guys ever taken the clock apart, or the back off?

Not in this 911 but my 1972 model had this happen at times. Took the back off and found that the points were burned. There is a set of points that make or break contact to rewind the spring. Took a small point file and cleaned them up and the clock worked great from then on.

Might give this a try... unless its a completely electronic clock.

Joe A

[MBEngineering]

HI Guys
have a look hear about your clock's;

DDK - Die Deutschen Klassiker :: View topic - How to Repair Your Clock

and see if yours are the same?

regards mike

[aston@ultrasw.c]

Originally Posted by Howard M

Have you been driving near the speed of light?

or close to any black holes?

[ossiblue]

Originally Posted by Joeaksa

Have you guys ever taken the clock apart, or the back off?

Not in this 911 but my 1972 model had this happen at times. Took the back off and found that the points were burned. There is a set of points that make or break contact to rewind the spring. Took a small point file and cleaned them up and the clock worked great from then on.

Might give this a try... unless its a completely electronic clock.

Joe A

The clock in his 76 is completely electronic, I believe, and so is the one in my 73, though it may be a replacement--not sure when the changeover was made.

If the clock face reads, "Kienzle" just above the 6, it has the points as described. If it reads, "Querz-Zeit" it is electronic.

[Nick Triesch]

Maybe you need to get your clock cleaned! Nick

[floete]

nick: har!

others: thanks for weighing in. i'm going to attach the clock directly to a 12v battery today and see what time it tells after a few hrs; that ought to rule in/out the clock itself.

[dshepp806]

may be some plenty old electrolytic caps that are wasted...then again, I;ve never studied that circuit

Best,

Doyle

[Nick Triesch]

My clock in my 85 carrera works fine with you are driving but when it sits off, it stops after about 5 hours! I checked the voltage with my meter at the clock and it reads over twelve volts. Also when you are driving it keeps perfect time which seems to say it does not need to be cleaned. Very strange these Porsche clocks! I changed the fuse, cleaned the contacts. Maybe a past owner died and is just messing with me. Nick

[RWebb]

my clock slows down in the winter

[nyne11]

ummmmm....A slow clock!

[floete]

update -- more help needed.

hooked the replacement clock up to the car's battery directly and it ran slow, so figured i had two slow clocks and sent the just-bought one back to the seller. he hooked it up to his power source and, yup, you guessed it, the thing kept perfect time.

so ... could it be a problem with my battery? if so, what could it be and what can i do about it, besides nothing?

tia!