thehackmechanic
Well-Known Member
[12/21/23 broken photo links repaired]
The clock on my '73 CSi had read 12:15 since I bought the car in 1986. As per a prior thread, I had pulled the speedo to repair the odometer, which will be the subject of a different post. But while I was in the neighborhood I thought I'd fix the clock.
This is the later-style quartz clock. I found a very good thread on the Pelican Parts web site; there doesn't appear to be much difference between the clocks used on the Porsche 914 and our E9s. They both use two types of clocks -- an early mechanical one with a separate back cover for easy access, and a later electric quartz one that requires the cover to be pulled off for the clock to spill its guts.
http://www.pelicanparts.com/techarticles/mult_vdo_clock_repair/mult_vdo_clock_repair.htm
With the clock out of the dash (pulled out from underneath), I first wired it directly to the battery just to make sure it was really dead. It was.
I then pulled my other clock out of the instrument cluster from the 2800CS I parted out many years ago. It was dead too. Since the faces of the two gauges are subtly different, I thought I'd fix the correct one (the quartz one), even though it is more difficult to crack open than the mechanical one.
I basically followed the instructions on the Pelican site:
--The chrome bezel holding the cover down has to be pried up; this is by far the most time-consuming part.
--The three small screws on the back have to be undone.
--There's a little solder cup on the back whose function is not entirely clear. What it is is the ground connection of the internals of the clock to the metal case. Once the bezel and face and the three screws are off, touch a hot soldering iron to this and the internal literally drop out. Be prepared. You probably want to position it face down on a facecloth, not a hard surface.
--You then remove a little round insulation circle and a foam insulation pad that prevents the back of the clock from shorting against the metal case.
The Pelican article references the frequent failure point as being the 47 and 100 microfarad capacitors. I don't have the ESR meter needed to do diagnose bad capacitors, so I simply replaced both of them. They were available at my local Radio Shack, part numbers 272-1027 (47 microfarad) and 272-1028 (100 microfarad), $1.49 each. If you can solder wire, you can unsolder the old caps and solder in new ones. Just remember to note which side of the cap you're removing is marked as negative on the side of the cap, and put the negative side of the new cap in that same hole. And go light with the soldering iron when installing them; you don't want to leave it on too long and pop anything.
With the new caps installed, I then applied 12V to the tab and ground to the post, and immediately heard and saw the little motor come to life. I waited a few minutes, and sure enough, the minute hand began to swing around.
I'm buttoning it up now. When you reassemble it, put the three screws in the back to draw the guts tight against the back of the case, then resolder the little ground post.
On the one hand, it was incredibly satisfying to, for three bucks, do what North Hollywood Speedometer would probably charge me $120 for (nothing against NHS; they do great work and would certainly clean and lubricate it while they're in there).
But I have to say, I have mixed feelings. I'd gotten so used to it always being 12:15 in my coupe. In a certain sense, time will begin to pass in my E9 for the first time since I bought it in 1986. Neither it, nor I, are immortal any more.
--Rob
The clock on my '73 CSi had read 12:15 since I bought the car in 1986. As per a prior thread, I had pulled the speedo to repair the odometer, which will be the subject of a different post. But while I was in the neighborhood I thought I'd fix the clock.
This is the later-style quartz clock. I found a very good thread on the Pelican Parts web site; there doesn't appear to be much difference between the clocks used on the Porsche 914 and our E9s. They both use two types of clocks -- an early mechanical one with a separate back cover for easy access, and a later electric quartz one that requires the cover to be pulled off for the clock to spill its guts.
http://www.pelicanparts.com/techarticles/mult_vdo_clock_repair/mult_vdo_clock_repair.htm
With the clock out of the dash (pulled out from underneath), I first wired it directly to the battery just to make sure it was really dead. It was.
I then pulled my other clock out of the instrument cluster from the 2800CS I parted out many years ago. It was dead too. Since the faces of the two gauges are subtly different, I thought I'd fix the correct one (the quartz one), even though it is more difficult to crack open than the mechanical one.
I basically followed the instructions on the Pelican site:
--The chrome bezel holding the cover down has to be pried up; this is by far the most time-consuming part.
--The three small screws on the back have to be undone.
--There's a little solder cup on the back whose function is not entirely clear. What it is is the ground connection of the internals of the clock to the metal case. Once the bezel and face and the three screws are off, touch a hot soldering iron to this and the internal literally drop out. Be prepared. You probably want to position it face down on a facecloth, not a hard surface.
--You then remove a little round insulation circle and a foam insulation pad that prevents the back of the clock from shorting against the metal case.
The Pelican article references the frequent failure point as being the 47 and 100 microfarad capacitors. I don't have the ESR meter needed to do diagnose bad capacitors, so I simply replaced both of them. They were available at my local Radio Shack, part numbers 272-1027 (47 microfarad) and 272-1028 (100 microfarad), $1.49 each. If you can solder wire, you can unsolder the old caps and solder in new ones. Just remember to note which side of the cap you're removing is marked as negative on the side of the cap, and put the negative side of the new cap in that same hole. And go light with the soldering iron when installing them; you don't want to leave it on too long and pop anything.
With the new caps installed, I then applied 12V to the tab and ground to the post, and immediately heard and saw the little motor come to life. I waited a few minutes, and sure enough, the minute hand began to swing around.
I'm buttoning it up now. When you reassemble it, put the three screws in the back to draw the guts tight against the back of the case, then resolder the little ground post.
On the one hand, it was incredibly satisfying to, for three bucks, do what North Hollywood Speedometer would probably charge me $120 for (nothing against NHS; they do great work and would certainly clean and lubricate it while they're in there).
But I have to say, I have mixed feelings. I'd gotten so used to it always being 12:15 in my coupe. In a certain sense, time will begin to pass in my E9 for the first time since I bought it in 1986. Neither it, nor I, are immortal any more.
--Rob
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