Left Rear Signal not working

02 Jetta. 350,000kms.
Started our with a left rear Tail light replacement.
Simple bulb replacement in -25 Celcius weather.
Now the left rear turn signal light does not work.
Rapid flashing on the Dash and the front and left front side lamps.
No Flash from the rear left bulb.
Bulb is good.
Removed the plug from the bulb module, No difference.
4 way flasher works OK, but still no left rear flash.
Are there 2 different flash relays, (Left & Right)
My next step is to get a Voltmeter on the wire, But it's &%$*&$# COLD out there, and no garage.

Any other suggestions from you Electrical Gurus

Make sure you replaced the correct bulb.

yep, double checked

Problem Solved

Found the problem.
Power at the plug, so I pulled the Bulb housing module and took it inside.
Much better to work in warm surroundings.
Turns out that all my bulb centre contacts were slightly corroded.
The Turn signal bulb was just a little worse.
I cleaned and put some contact fluid (used in the Aerospace industry to prevent just this kind of problem).
Everything worked fine.