Packard Forum Index » V-8 (1955-56)

can someone tell me what flasher this car is supposed to use? I had a tungsol 273 in it for a little more than a month and the worked correctly then failed yesterday. I bought a Napa unit but that causes the panel indicators to behave oddly..

I am not familiar with anyone else who might be using the NAPA 12v flasher replacement on a negative ground car but I can speak from experience - both mine and others on the forum - the 6v NAPA universal replacement listed for the 51-4 models will not work the indicator lights on Packards with positive ground.

That particular 6v flasher has a regular thermal section to work the outside bulbs which do work well but has a transistor to work the indicator bulbs and the transistor is the wrong type for positive ground cars. Perhaps the NAPA 12v unit also has a transistor for the indicator bulbs and while it might be the correct polarity, might not have the correct operating characteristics for incandescent indicator bulbs. When you say "behave oddly" what are they doing and do the outside bulbs work properly?

There is a cross that another poster found -- the Novita EL13 sold by O'Reilly and Amazon -- that apparently will work but I have not personally tried it.

I haven't tried this one personally, but I am currently using their 6V positive ground LED-compatible flasher. It seems to work very well and is more tolerant, not only of lower-current LED bulbs, but also the state of ground connections which the original flasher was relatively intolerant of.

ledlight.com/round-flasher-led-compatible-12-volt-dc-150-watt-2-terminal.aspx

The odd display behavior is the right indicator on the panel blinks when the left turn is selected and both panel lights blink when the right turns is selected, they only come on dimily

Your using that flasher in a 56 12 volt negative ground car?

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:

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  49-56 Turn Signal Extraction2.jpg (220.79 KB)

Thanks for your response, the diagram confuses me some, there is a dashed line between the panel displays on the side of the blub I would expect to be grounded, what is it that's going on there? it appears that it means its there on later cars so the current path is from the turn signal switch (ie orange wire) thought the blub to flasher to ground? is that correct?

You have every right to be confused and are the first to catch -- or at least report -- an error in the drawing. Kind of makes me wonder how many have actually looked at the drawing since it has been posted several other times. I do apologize for not catching the error a long time ago.

The indicator lights on the first drawing were mislabeled as to right and left. As the drawing was originally, neither indicator would have ever lighted since the voltage would be the same on both bulb terminals. I have replaced the drawing on your post and corrected that mistake. The dotted lines are only meant to differentiate the 49-52 single bulb indicator circuit from the 53-56 dual bulb indicators.

Functionally, both indicator lights get voltage from a separate contact in the flasher at the same time the flasher sends voltage to the outside bulbs. The indicator to be lit gets ground thru the OPPOSITE side bulb which will not be powered and is at the time unconnected from the turn signal circuit. That wiring does place two bulbs in series but rather than both bulbs lighting dimly, since the outside bulb has a much heavier filament and requires considerably more current to light than the small indicator bulb, it will barely be affected and will be so dim as to remain unseen. Even though it is powered, the indicator light for the side not supposed to flash will still remain off because of the same voltage being on both sides of the bulb.

Howard; I think the diagram is OK.

Assuming the pilot and load are synchronized, then let’s put the right turn signal ON and analyze the circuit when the Orange wire is ‘hot’. Both the Orange and Pink are ‘hot’ resulting in zero voltage drop across the left indicator . . . that is when the right turn signal is ON, the left indicator is not producing light. That seems correct so far.

With the Pink wire still ‘hot’ the right indicator will be powered, and have a ground path through the Left turn signal bulb. Since incandescent bulbs have less resistance when cold this ground path is sufficient to provide enough voltage drop across the right indicator to produce light. Seems that’s correct also.

dp

Howard; I think the diagram is OK.

David, The original diagram I had posted in this thread which caused Bill's confusion had the right and left indicator lights mislabeled. I replaced that drawing with the one currently shown which is now correctly labeled and your description is correct.

The original drawing was done for someone with only a single indicator bulb. After drawing and posting it I realized the later circuits were very similar. Then hurriedly drew in the dual indicator bulbs as an afterthought. Placed them next to the outside lights to fit the wiring in near the single indicator bulb and then got in too much a hurry and mis-identified them by matching the labels with the outside lights.

The original version had been incorrect for several years and numerous postings before Bill questioned the operation and I realized they wouldn't work the way they were labeled.