MG Car Repair: key & ignition, test light, switch assembly

Question
I have a 1978 MG Midget.  The car will start, however, I have to hold the key down to keep the engine from killing.  Is this due to the ignition switch needing to be replaced or do i need to replace lock steering switch assembly?  The difference is about $90.  Thank you.

Answer
Hi Michele,
You should never replace any part until you know what is wrong and what part failed. The ONLY way to find out is to test.
In this case you need to remove both white w/light green wires from the coil and separate them. Then turn the key to the "ON" position. Test each of the two wires for power. Only one should be powered. Put that wire aside and put your test light on the other wire and turn the key to the "Start" position and that other wire should get power.

If that is not what the wires do then you need a wiring diagram to start tracing backwards from the "dead" wire to it's power source.

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

Howard