Kienzle clock

[Donels]

My +2 is disassembled and I am currently working on the dashboard and instruments. The Kienzle clock is a puzzle. The mounting strap is liberally covered in red electrical insulating tape and there is a band of tape around the clock where the strap would contact. On the back of the clock are 2 + positive stamps. I suspect that a PO fitted a positive earthed clock in a negatively earthed car and bodged the wiring to suit, but my photo's do not cover this detail. Anyone know if they were available in positive and negative versions, and can it be easily changed?

[bob_rich]

Hi Donals

can't really comment on the need for the red tape. I would have thought, but cannot be 100% though I would bet on it, that the clock in standard form being purely electro-mechanical ( no electronics) that it would work on either +ve or -ve earth without any adjustment.

if the PO has tried to reverse the connections the outer bezel may become live at 12V and that could be nasty if some accidental metallic contact shorted it to the main body such as another instrument case

Perhaps others will comment

best of luck Bob

[JonB]

Should work irrespective of polarity. Remember though, the electromagnet?s poles will be reversed and this could hinder the winder arm.

You say there are two + marks stamped on it? One could be on the regulator screw (adjusts how fast it runs). Need pictures please. Is your car positive Earth?

Be careful with the clock. They are easily damaged (physically and electrically) and the bezel is a devil to remove intact. If you break it I can probably repair it for you. I had a lot of experience fixing my own, which I documented in two recent threads.

[edit: here are the links]
Clock rebuild (stared off as a "wanted") thread : viewtopic.php?f=4&t=45119
Clock protection circuit: viewtopic.php?f=38&t=45385

Good luck
JonB

[Donels]

Problem solved. Cleaned all the crap off and there are two + marks, one for +/- adjustment and the other indicating the positive terminal. The clock has been replaced or repaired at some point and a non-standard strap fitted. This is much wider than the correct strap and can touch the + terminal causing a short circuit, hence all the insulating tape.