Here is my fix for the clocks - Replace the Zener and resistor with a switchmode power supply.

The original resistor has to dissipate almost 1 Watt.  In an enclosed space, where the sun can heat it to over 120 F ambient.  It runs so hot, it oxidizes the solder.

 

 

The second part, is adding a diode and capacitor to the always on line that keeps the clock keeping time when the car is off.  But any glitch in the power can reset it to 1:00.  The capacitor holds some power to keep it alive for a short time.  The diode stops the energy from the capacitor from going back into the car electric system if you remove the battery, or use the starter.

 

Thank you for this!

Care to fix one for me?

 

Have 4 that I can send you, only need one back.

Hey Dave

I need one fixed also!! Any chance of a how to video for this?That seems to be a little too high tech for me.........

Thanks

I have to come up with a power supply I can get more of. I could do some, maybe trade for parts or something? Most of mine have the same failure.

With 4, I'm sure at least one will be fixed by doing this mod.

Is it possible to replace those parts and use them on the car without modifying?

 

Regards,

 

Sam

The problem is caused by the amount of power dissipated in too small of an enclosed space. The common failure is the solder corrode and opens the circuit. You don't need to replace the parts,just re solder. BUT it will just fail again. If a bigger wattage resistor were mounted outside of the clock, it may work indefinitely. The other mod is separate , it just makes the clock more resistant to power glitches.

I've solved several clock issues simply by resoldering the "dry" joint.
Just pull the clock apart and go from there, what needs to be done should be obvious!

Cheers

Bennie

I pull the resistor right off the board, then solder on some wires at right angles to the ones on the ends of the resistor, then solder it back in so the resistor is way up above the board, on legs.  This keeps the heat away from the board, so it doesn't deteriorate again.

 

Works for me here in Canada.  Might not work so well where it gets hot.  But it will work better, and be a bit easier than wiring in a new power supply.

 

I pull the resistor right off the board, then solder on some wires at right angles to the ones on the ends of the resistor, then solder it back in so the resistor is way up above the board, on legs.  This keeps the heat away from the board, so it doesn't deteriorate again.

 

Works for me here in Canada.  Might not work so well where it gets hot.  But it will work better, and be a bit easier than wiring in a new power supply.

Is There any chance you could post a picture possibly with some instruction? to identify the different parts.?

Thanks

Edited January 2, 201511 yr by subarusaver