Originally Posted by duggravs
I changed all my lights to LEDs on my 63. Front and rear. The turn signals work perfect until I turn on the headlights.
I got this led flasher AUDEW 2-Pin Electronic Turn Signal Flasher Relay Fix Motorcycle Turn Signal Hyper Flash https://www.amazon.com/dp/B011BTMDQM..._pY6yzb2854SY5
When the headlights are on. Both turn signal indicator on the dash turn on. But when i turn off the head lights it starts flashing again like normal. Could it be the flasher or something else?
I looked at the flasher you got and I really doubt that is the issue BUT I do like that one in that there is an adjustment on the bottom for speed.
On your car, and a lot of other GM's from that era, the front parking lights/turn signal lights are on a common ground and basically there are three connections on the bulb.
When things are right, when you pull out the headlight switch, the parking lights should come on and the low wattage portion of the turn signal/parking light bulb should illuminate and both the indash turn signal lights should be off.
Now if the headlights are turned off, so should the parking lights and then if the turn signals are activated, the higher wattage portion of the bulb will illuminate.
If the headlights are on with the parking lights lit up on the low wattage portion of the bulb, when the turn signals are activated, the bulb will go from a low glow to a high glow as the low wattage portion of the bulb is already lit up and then the turn signal portion of the bulb being a higher wattage, will make the light brighter yet.
BUT there can be issues if one or more of the light sockets/bulbs are not grounded well and I think this is your issue. When the parking light/turn signal sockets up front are not grounded, then when they are fed 12V from the headlight switch in the parking light mode, they are trying to find a ground and then since there is none, power gets back fed into the turn signal wire which then is wired to the indicators in the dash and then those illuminate also.
While you may have an issue with one or more of the light sockets not grounding well or the structure they are bolted to is not grounded well, it's real easy sometimes to get the bulbs in wrong. The bulbs with dual filaments (1157 models) have 2 nipples on the bottom and on the sides of the barrel, they have locking pins sticking out and one is at a different height from the base of the light than the other and these pins have to line up properly with the different offset notches in the light socket. I have seen poorly fitting bulbs and/or sockets and you can get them installed 180 degree's out.
I would first double check your front end light sockets and mounting for good grounds and then make sure the bulbs are in properly.
If things still are not right, I would make sure the new flasher is wired right in that there is an input and an output. I really doubt that this is your issue BUT who's to say sometimes.