Fuses

With the few fuses the MGB has it is always a good idea to have spares on hand.
I had a fuse that looked perfectly fine but was burned out. It's always best check your fuses before thinking there is some kind of wiring problem...

I found this blurb on a MG repair site that is helpful:"Lucas is very good about color codes and what they do.
browns are power
blacks are grounds
whites involve ignition
purples are hot all the time
blue are head lights
reds are other lights
greens are accessories
When they use a colored stripe it is usually a modifier of the color for example, a green wire will operate an accessory and a green wire with a black stripe will be grounding operational wire for that accessory. Like a white wire is ignition wire and a white wire with a black stripe will be a grounding wire for the ignition system. This is general but it helps when trying to locate problems. "