Packard Forum Index » V-8 (1955-56)

I'm looking to replace the flasher on my '55 400 with an electronic unit, replacing the stock P273D Tung Sol mechanical flasher, but I've been unable to determine if the socket is a CF13 or CF14 type, which determines the pinout polarity. Does anyone know which socket is applicable to the positive ground system?

I don't have a schematic or enough information on the flasher requirements to help on the specific question. As to the polarity, in 55 the negative battery terminal feeds the socket terminal for incoming flasher power and the positive ground is thru the outside light bulbs. Back in the day the old thermal flashers did not care about polarity so all Packard had to worry about was getting power to the flasher input terminal and the proper output signal to the bulbs. Sockets were wired the same from 51-56.

There is an adapter that claims to be able to let the flasher use both type sockets so if it changes the input to the flasher that might be an option. Again, not enough info on the flasher requirements to know if the adapter can swap polarity to the internal solid state components. I expect those are looking for a negative ground.

As to the Packard wiring, the terminal names were different then so without more info can't say which modern terminal designation to cross to the old but if the + and - designations on the flasher are what it expects and your 55 is still positive ground, on the flasher Amazon shows B1+ would go to the old 1 and -1E would go to the old 3. Assume L would go to the old 2 but all that is just a guess on my part and could be completely wrong. No idea how modern turn signals are wired to correspond to the terminal designations on the electronic flasher.

Here is how the Packard sockets were wired.

Terminal 1 (L) is the flashing signal to the outside bulbs thru the turn signal switch.
Terminal 2 (P) is the flashing signal to the panel indicator lights
Terminal 3 (X) is power in from the ignition switch thru a fuse

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Based on that wiring diagram the socket doesn't match either standard, so no electronic flasher will work without wires to change the pinout. I was already looking at the one that came with the adapter but if one of the standards were adhered to I could get one with adjustable rate. For that I guess I'd need to make my own adapter.

Thanks for the info.

I believe there were adapters without flashers on Amazon and maybe on ebay too so perhaps one of those plus the adjustable rate flasher could be used.

I just converted my '51 to 12v and installed a novita 552 thermal flasher and it works great.

For future reference, I obtained the electronic flasher with adapter and can report that it doesn't work in the '55 no matter what pinout is configured. I tried every combination.

Was there any kind of schematic with the flasher as to what the pins do or anything on the internals? Am assuming it did not work because of the positive ground in 55. Wonder if it would work on a 56 of if there is some incompatibility with the way the Packard switch selects the bulbs and starts the flasher going.

Just what's printed on the flasher, as pictured above.

I figure it's a polarity issue. Solid state devices tend to be quite picky about such things.

Jason75 ...Excuse my ignorance but Did your indicator bulb in the instrument panel blink when the Turn signal lights blinked. Or did the indicator light just come on solid? I'm not familiar with what it should do. I have a 51 packard 200 deluxe and need correct 12v flasher number. I converted from 6v positive ground to 12v negative ground.

The dash indicator lights flash. The combined brake/flasher systems with shared rear bulbs used from 49-52 had a single indicator and 53 on had an indicator for each side. A solid indicator light or one that gives a single brief flash then nothing typically means the signals are not flashing and the cause has frequently been traced to a bad ground at one of the bulbs on that side or a burned out bulb. On a few occasions it was found a miswire to the bulb sockets had the filaments reversed and the small tail light filament was being used for the turn signals.

The old thermal flashers are not polarity sensitive but are very dependent on needing a certain amount of resistance from the bulb filaments being in the circuit. A total resistance that is too much more or less than the required amount will change the current the heater that works the bimetal strip in the flasher needs. It either will not heat enough to flash or heats so much or so quickly that the flashing is very rapid. Electronic flashers use solid state timing circuits and are much more forgiving on the total number or size of bulbs they are connected to but are polarity sensitive.