Re: 1956 Clipper Turn signal flasher

Posted by HH56 On 2021/9/28 11:12:36

The flasher has two independent contacts. Voltage in via X is switched on and off with outside lights powered via L and indicators via P. The flasher starts its action by the blue wire being connected in the turn signal switch to the bulbs. That connection provides a ground to the thermal element which controls the flasher because it is now in series with the bulb filaments. The element starts heating bending a bimetal contact which energizes the relay like portion of the flasher to bring in the main contacts. When the relay contact closes to light the outside bulbs, the heater is bypassed so no voltage and it cools breaking the circuit so relay drops out. As soon as relay contact drops out the heater starts heating again and cycle repeats as long as the thermal element is connected to the bulbs.

The P supplied voltage on the dotted line is the one which goes to both indicator lights at once but since the side flashing also gets power, the indicator bulb also connected to that side cannot light. That only lets the other indicator bulb get ground via being in series with currently unpowered and unconnected outside bulb filaments on the non flashing side. The bulb flashes in sync with the selected outside lights. That particular indicator bulb is placed in the dash to be the indicator for the same side as the outside bulbs selected to flash.

Not knowing if anything has been done to the wiring and something changed in your car, I am still thinking there is a grounding, poor connection or a bulb issue -- but since I do not know of anyone else using the Napa 12v flasher there is the chance the flasher has some issue just like the Napa 6v version. That one works outside lights just fine but does not work the indicator lights properly. If I understand you correctly, when turning the key on your indicators light up without the turn signals commanded and that would indicate voltage leaking thru the flasher so could be a flasher issue.

I do not have an old catalog to verify the Tung-Sol number you have to what was used originally. Perhaps someone has a reference and can post the number to verify your original was correct. The thermal flashers are resistance specific and generally are very erratic if they work at all when used outside the design parameters. If a number is found and yours was incorrect there is a good chance an original can be found on ebay.

Another thought is since the issue is only with indicator lights, also make sure the indicator sockets do not have a problem. The socket shell must be isolated from any other grounds so there is a fiber insulating washer like affair between the prongs that hold the socket in the dash and the actual grounded shell. Make sure nothing else can connect with the shell and provide a second ground path except the wire attached to it.