l have tried everything l can think of ,,fuses good bulb is good conection is hot,,, but light wont come on left side works fine
any ideas?

Purchase a NEW Headlight, the connection an everything may be good but the BULB'S 'low' beam filament is 'out', not working (REPLACE the Whole Lamp)
You're Welcome..... ;-)

It could the bulb,fuse or relay,check all three.

right in the fuse box there is a small black box that controls a lot of the cars lights. This box is at fault. to remove it just give it a yank up. Then crack it open and look for bad solders. This is yet another one of the many many design flaws of the 735i and all BMW is after.

Are you also experencing the dash lights going off and you have to turn the headlights off and back on to get the dash lights to come back on?