when you turn on left signal light both rear light blink/AC blower stops/back up

Hello, You have an electrical issue, as you know, and the failure may be in the fuse panel, body control module, or just open/shorted wires. The reason I automatically think the issue is involved with the fuse panel is that all of these systems do have wiring in the steering column. Be fore-warned, this may be a difficult problem to diagnose, but it also may be very evident to the trained eye. Using a Jaguar trained technician, or jaguar specialist will likely save lots of diagnostic time. You may have to call the different shops on this list to find one with a factory trained Jaguar specialist, unless there is a specialized shop. http://repairpal.com/jaguar-within-10-miles-of-baldwyn-mississippi-38824