FIXING THE MORGAN/ROVER 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 putback 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 Center feed (direct from battery)
2. First position of the key in ignition. WHITE with GREEN tracer. (power to fuel pump) 3. Second
position of the key in ignition. WHITE. (to ignition switch powered items)
4. Third position Starter engaged. 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.