It depends on wether the flasher unit is the old sort with bimetallic strip or electronic.
Bimetallic strip will be affected, how much I could not say.
Electronic one won't be, it will still give a on/off signal with nothing connected.
tabetha
ps no not self levelling, but not set too high either, just readjusted my lights DOWN on me astra after being set on MOT machine as too high!!!