FIXING THE MORGAN IGNITION SWITCH
by Dennis O'Neal MSCC 7564 1990 Plus 4

GoMoG thanks Dennis for offering this article for posterity!

Problem started with the key being too stiff to turn easily...then refusing to turn at all without some force. Finally not being able to remove the key or turn it. At the final stage I had to turn the key using pliers so to start the car or to remove the key. I checked on the internet to find this problem was not uncommon and occurred on many vehicles using the same type of switch made by Lucas.

On the rear of the switch there is a black plastic molding (see first image below) which is held into the main switch body by a small threaded screw. My son removed this and pulled out the plastic switch part (plastic multi-connector) which was linked to the ignition key part of the main body. This was the main electrical switch for the car.

On checking the ignition key we found it turned without any problem and then checked the rear switch operation using a screwdriver to turn it. It was very difficult to turn so we had found the problem. He then removed the cables from the car. He found it was better to remove the steering wheel and work under the dash to give himself more room. This round black plastic unit is clipped together and we managed to take it apart to find ramps had been made over time on the internal contacts. We used a Dremel type tool with a small stone to clean and level up the contacts and rebuilt the switch (not easy) after lubricating the contacts found it would turn smoothly. When put back into the switch body everything worked like new.

Thinking like many others the whole switch would have to be replaced I had ordered a new one which arrived and on checking the problem rear plastic switch found it was much larger and looked stronger. Apparently, the manufacturer knew they had a problem and impirved it since 1990. Lucas also supplied this switch body SBB307 at around £15. This has two extra cables which I removed and one extra cable terminal which I insulated so I have purchased one ready to fit if our repairs do not last.
The beauty of repairing or replacing the or rear plastic switch if this is where the problem is you do not have to remove the main switch from the steering column.

IGNITION SWITCHES, OLD AND NEW REPLACEMENT Lucas SBB703 switch.
INTERNAL PIECES

1. BROWN Centre feed (direct from battery)

2. First turn of the key in ignition. WHITE with GREEN tracer. (power to fuel pump)
Second turn of the key in ignition. WHITE. (to ignition switch powered items)
Third turn. Start the engine. WHITE with RED tracer. (To starter starter solenoid)

The switch is a MG sourced part and has a extra spade terminal which I removed the cable then insulated the terminal. Also a another cable used for a alarm if key was left in the car ignition. This is not attached to the rear switch on the ignition switch but goes to the multi-plug. All other cables remain the same as original ones but are connected to a plastic multi plug which needs to be cut off and cables fitted with solder on bullet connectors so to be plugged into the Morgan main harness.
I was also lucky that a very good Morgan owner friend who had a switch which he had removed and replaced with a new one and he sent it to me. So I used it to find out where the problem was. After stripping and cleaning the contacts I found the switch was working perfectly so replaced it into my main switch on our car which it still remains and working like new. The original rear switch is now repaired and fitted to the one my friend sent me.