Re: 1956 Clipper Turn signal flasher
Posted by HH56 On 2021/9/20 17:39:57
One frequent problem with Packard turn signals is bad grounds at the housings and corrosion in the sockets and connectors or corrosion between the socket and potmetal housing. With the symptoms, it almost sounds as if you have a grounding issue and various bulbs are trying to find a ground path by going thru a secondary path. Because the two filaments in the bulb are connected together as well as two bulbs maybe in parallel, if the turn signal filament does not have a solid ground it sometimes finds a better ground thru the other filament like the parking or tail light filament and then thru a connecting wire to another bulb and its filament.
Electronic flashers will operate consistently with just a proper voltage even if a bulb is burned out but with the thermal types, it only takes a small amount of rust and corrosion or a burned out bulb to change the resistance in the circuit. The way thermal flashers work is very dependent on having the amount of resistance in the circuit at a fairly narrow range the flasher is calibrated to operate with. If the resistance value is not met they flash erratically or not at all.
Rust frequently happens at the sheetmetal to mounting screw contact places as does corrosion building up a layer of insulating oxides on various pieces of potmetal that are supposed to touch and carry the ground to the sockets. In many cases the issue is so bad on potmetal pieces that cleaning the mounting isn't enough and owners have had to actually run a separate ground wire and attach it directly to the socket and then screw the wire to fender sheetmetal. .
Before spending any money on another new flasher I would suggest you go thru and inspect or clean every ground you can find at the park and tail light housings. Unscrew the bolts or screws to get under the head or nut to clean any rust on the sheetmetal or on the screw or nut.
Here is a breakdown of just the turn signal circuit showing the path thru the switch. The switch shown on the drawing is the 49-54 version and while the 55-6 switch is physically different, electrically it is functionally the same.
Attach file:
49-56 Turn Signal Extraction2.jpg (220.79 KB)
Electronic flashers will operate consistently with just a proper voltage even if a bulb is burned out but with the thermal types, it only takes a small amount of rust and corrosion or a burned out bulb to change the resistance in the circuit. The way thermal flashers work is very dependent on having the amount of resistance in the circuit at a fairly narrow range the flasher is calibrated to operate with. If the resistance value is not met they flash erratically or not at all.
Rust frequently happens at the sheetmetal to mounting screw contact places as does corrosion building up a layer of insulating oxides on various pieces of potmetal that are supposed to touch and carry the ground to the sockets. In many cases the issue is so bad on potmetal pieces that cleaning the mounting isn't enough and owners have had to actually run a separate ground wire and attach it directly to the socket and then screw the wire to fender sheetmetal. .
Before spending any money on another new flasher I would suggest you go thru and inspect or clean every ground you can find at the park and tail light housings. Unscrew the bolts or screws to get under the head or nut to clean any rust on the sheetmetal or on the screw or nut.
Here is a breakdown of just the turn signal circuit showing the path thru the switch. The switch shown on the drawing is the 49-54 version and while the 55-6 switch is physically different, electrically it is functionally the same.
Attach file:
49-56 Turn Signal Extraction2.jpg (220.79 KB)
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