The two sides can't be different so something is wrong there. For now, what is the symptom? Do the left signals light up but not flash or do they not even light up? If they light up but don't flash, that is because there's not enough current flowing through the flasher to warm up the heating element, and that is caused by one or more bulbs burned out, so yes, check the front bulbs to see if they're lit up.
If the bulbs don't even light up, front or rear, on just the left side, that could be due to a defective signal switch or a break in the wiring. If it's the signal switch none of the bulbs will light up. Depending where a break is in the wiring, you could have the front one light up but not the rear, (that's the most common failure), or they all could not light up. The additional clue is if you turn the signals off, then the left bulbs work with the brake pedal pressed, as they should, that proves the wiring to the rear is okay and the problem is likely the signal switch.
There could also be a break in the wire going to the front signal bulb. That one would not light up but the rear ones would. They just wouldn't flash.
Tuesday, May 7th, 2013 AT 8:10 PM