The wires at the front left turn/park light socket.
There are 3 wires there, plugged onto 3 separate prongs. Parking light,
left turn/flasher, ground.
If someone plugged the ground wire onto the wrong prong then the bulb
voltage will feedback into the other light circuit instead of to ground.
Another common possibility as someone mentioned is that the wrong bulb
is installed. The socket is designed for a bulb with 2 contacts on the
tip. If someone put a bulb with only 1 contact, that contact will bridge
the 2 socket contacts and feedback the bulb voltage to the other circuit.

Mark

> Which wires Eric?
>
> Ben
> vw4x4@fyi.net wrote:
>
>> I had this happen.   The DPO had removed the
>> wires and installed them in the wrong place.
>>                                     Eric
>>
>> Benny boy wrote:
>>
>>> Gentremen's...
>>>
>>> Van is an 83 Air-Cooled.
>>> Parking light ON, rear left flasher goes ON????????????????????
>>>
>>> Any other way, everything is fine with the flasher, but if i put the
>>> parking
>>> light ON, left flasher stay on and doesn't blink if i try to.
>>