1937 Buick Clock Recall

[BuicksBuicks]

...well not really. There is no recall. However this is the second time I've found a broken solder joint in a 1937 Buick clock.  It's not easily seen so I've attached a photo of the repaired solder joint. The "wire" used in this connection is extremely stiff and springy and almost certainly the cause of the fracture. I first came across this problem around 1962 with my first '37 Special; now I've come across it in my latest '37.   Just thought I'd throw the info out in case anyone had given up on their clock repair.  -Pete

[Jack Worstell]

I have come across this twice also.     I've been able to re-solder using a small battery powered soldering iron....it's tedious.

 

Jack Worstell                        jlwmaster@aol.com

[LAS VEGAS DAVE]

What happens to these connections is that the battery slowly dies in the car when they sit for long periods. Eventually they get to low for the battery to power the electro magnet in the clock. The clock winds down and the points close but not enough power for the electro magnet to lift the winding arm which normally opens the points at that time. Since the points stay closed but there is some juice left in the battery the wire gets hot, it can melt the solder or burn out the electromagnet coil. If the car is going to be stored the battery should be disconnected or left on a trickle charger.

 

[Joseph P. Indusi]

I have seen this occur in many electronic circuits as well, generally brought on by excessive heat as stated above by Las Vegas Dave.  My observation is that the solder forms a crystal like composition and develops cracks.   These cracks on a circuit board are very fine but just wide enough so that continuity is lost.  I have repaired oil burner relays, radios, TV's, power supplies in paper shredders, etc. by just finding and then re-soldering these defective solder joints.

Joe

[BuicksBuicks]

Las Vegas Dave hit the nail on the head.  The link that opens is actually a crude slow-blow fuse that heats up and opens when the battery is low; without it a weak battery will turn the relay coil into a 23 ohm heater. Since I don't want to open up the clock anymore I will be adding an external slow-blow fuse, maybe one or half amp.  There is another fuse on the back of the clock; in my clock someone replaced it with a 20 amp. Not knowing what the original fuse rating was I figure that I can get along with a 2 amp and see what happens.  The re-soldered link has now been soldered with modern 63/37 solder which probably disables its original fuse function. Some current measuring comes next to see what the minimum drain is with the dash lights on.

 

Thanks all for the comments!