One of the many small electrical niggles on my '71, is that the 'door ajar' warning light doesn't work. This is a prompt I can happily live without, but since it's there, it ought to work. Probably the bulb is dead I think - not surprising after 50 years - so having removed the instrument dash panel to attend to more major problems, I check the bulb while I'm at it. Somewhat disappointingly the bulb is sound, so the problem lies elsewhere.
The lamp circuit is controlled by a plunger switch mounted low down in the rear door shut face and is activated by a rubber pad stuck to the door panel itself. With the door closed the switch is in the open condition. When the door is ajar the plunger is released and closes the switch to ground the live supplies to the lamp and the alarm (if activated).
First inspection shows that the rubber pads are missing (probably not refitted after a previous respray). If the switch is working then the lamp should be on all the time, so I unscrew the switches. The contacts are missing so Bubba has at some time decided to deactivate the switch. Both the switch and the metal plate it screws into are in very poor condition so I decide to replace both. I drill out the pop rivets and the old plates drop off. The design of this switch is not very impressive. The contacts are a press fit in the plastic body and rely on friction to retain them. Unfortunately the switching action - that occurs every time the door is opened - acts to push the contacts out again and some owners trying to replace contacts in an old switch unfortunately find they push out after a few operations. If needing to replace switch or contacts, it's best to replace both. The switch and contacts are sold separately but I find two switches from Claremont and a set of contacts and the metal plates from CK. Originally the contacts were swaged onto the cables but I prefer to replace them with a soldered connection and since this is easier done on the bench, I assemble the switches with short pigtails to be later attached to the cables in the car on reassembly.
Since they were no longer attached to the original switch the cabling in the car has retreated to somewhere between the body and the 'B' pillar. Access to this area is through a hole covered by a small plate in the rear wheelarch. With this plate removed the cables can be retrieved.
Replacing the steel switch plates poses a problem. The only access to the inside of the body is through the wheelarch hole and then outboard there is a small hole in the 'B' post through which the cabling passes. This hole is too small to pass the plate and the alternatives of either major surgery or complete body removal to fit it are not attractive.
The plate actually only needs material to allow riveting to the body and the 3/8" UNF thread for the switch, so I trim it to retain just these features.
The plate will now pass through the hole - but my hand won't - so some method of holding the plate to the body while being pop riveted is needed.
I cut short length of thread from a 3/8" UNF bolt, drill a 3mm hole through the centre and cut a slot in one end; this I screw through the modified plate and pass a length of cable with a knot in the middle through the hole.
I tape the knotted end of the cable to the three wires, feed the unknotted end through the access and 'B' post holes and out of the switch hole.
I manipulate the plate through the 'B' post hole, pull on the cable to hold the plate firmly against the body and ensuring that the holes in the body and plate line up, fit the pop rivets. The thread length is unscrewed from the plate and the cable pulled through to bring the taped on wiring out through the hole....
The new switch pigtails are soldered and sleeved to the three wires ....
.....which are then pushed back into the body and the switch screwed into place - simples!
As a final check I fit the switch plunger with a small plastic collar and close the door to see if the plunger moves before fitting new rubber pads. It does, but only about a millimetre...
....so I ensure there is enough travel left to accommodated the thickness of the pad and a blob of white paint on the end of the plunger marks the door with the exact position for fitting.
I still don't have my instrument console back in the car (waiting for parts from the States) so I don't yet know if my repair works - still I'm hopeful!
Incidentally, while rummaging around in the cavity behind the wheelarch assess panel I unearthed this
It's a slab of semi-fossilised rubber foam - about the size of your hand. I've no idea if it's meant to be there or if so, what it's meant to achieve. If anyone has any ideas - I'd love to know.
