Technical turn signals

Need some help with turn signals. Right works fine, left rear works left front doesn't , bulb is good. Been chasing wires can't fine anything. Any suggestions?

 

Check your ground for the left front.

 

Pull the bulb and with a test light or voltmeter check for voltage at the bulb contact. If you have voltage check for previously mentioned ground issues. If not start at the source and check for voltage at turn signal switch. Factory column and switch or a add on?

 

It's a after market switch. The parking light works and rear urn signal works, I will check the switch this morning. Switch is working fine, if I take the bulb out the dash light blinks install the bulb nothing happens? New to this stuff could it be a short?

 

try a good ground to the lamp socket that you are certian of as in right fro m the battery to the socket. Grounds can be very mysterious at times.
You could also take a test light and ground one lead and trace the voltage coming out of the switch to the wire and see if the testlight flashes.