booch,
correct, there are three control unit blocks on the headlight.
All I wanted to say is that the one at the bottom is known to be available from the marketplace.
Before buying a new one David should check if it is damaged by exchanging left and right units.
But the first step in troubleshooting now should be to exchange the complete left and right headlight unit to find out if the flasher malfunction goes to the other side.
David,
if you have installed Plontines DRL module, the cabling at the headlight side should be long enough to allow for plugging in the left headlight in the right wiring loom and vice versa. Just for functional test. Of course you will have to disassemble the car front to remove the headlights and place them on the other side.
Moreover, if you have a fast responding DC ampere meter with about 3 A measurement range, you could disconnect the single-wire flasher connection (see picture) and put the meter in between. By this you can measure the current consumption of the flasher. Should be equal on both sides and in a range of approx. 2 A.
Plontine_TurnIndicatorConnector_after_IMG_20210926_184832__.jpg