MG Car Repair: Electrical issues, hazard switch, electrical issues

Question
Hi, I recently purchased a 71 mgb. All light were working. Last night I replaced the bezel around the hazard switch by removing and replacing one wire at a time to be sure to get all the wiring in the proper locations. When done replacing the bezel, and put everything together, the radio, courtesy light and headlights aren't working! Could all of these be related to something I did with the hazard switch? Any help would be greatly appreciated.

Answer
Hi Dan,
While it is quite possible that your work did something to cause the other problems the possibilities are endless. Do this first, check the wires plugged into the head light switch and wiggle the fuses.

If you don't get any results take out your wiring diagram and test light and start tracing circuits.

I found while working in dealerships that my best method was to pick ONLY one circuit (usually the easy one when several were dead) I start at the "Load" (item that don't work) Turn it on and check for power and check the ground. (check them electrically with the test light) Then with the diagram follow the color code wire and check at each connection as you head toward the "Source" (power supply) This is a 100% correction method. Most of the time if you have several items out it will correct all of them. Forget symptoms as symptoms are usually 100% useless. Testing is the only method to correct an electrical problem.

If you don't have a wiring diagram, let me know and I will put one up on my web site for you to copy.

Howard