Notes on 240 Volvo Ignition Switch and Lock


This is about the ignition switch and lock ...




A lock, switch and connector are shown. Locks vary over the production years in some detail, e.g. the 1993 incorporates a cable driven lockout of the automatic transmission shifter. Switches changed with airbag (90-) cars and are not interchangeable.



The switch is removed from the lock with a 3/16" slotted screwdriver. The photos here should give you a clear enough picture to use in getting a short screwdriver into position without lights and mirrors.



Steering interlock depends on key insertion and key rotation.



I've since found there are two pins, and if you scroll down some, you can see them and their removal.



This depicts testing the "S" terminal of the ignition switch, used to signal the key insertion. Continuity is made when the lock pin extends. Poke it with a screwdriver to test it.



Likewise the remaining circuits can be buzzed out using a screwdriver to rotate the switch through its positions. As always, a true test is done by measuring voltage drop under full load.



If the switch needs further diagnosis, the pot metal needs to be uncrimped from the Bakelite to disassemble the switch. I've seen overheated spring contacts resulting in intermittent operation.



Here's how it is assembled to the steering column in a 1991. The casting is pressed on rather than being clamped on. Some brief research in the parts fiche has me thinking there are distinct versions for pre-airbag, 90-92, and the 93 which operates the shifter interlock for automatics. These post-86 locks are indeed different from the clamp-on-the-column version I show from the 83 above. Those have a column diameter where they attach of 37.5 mm contrasted with 43.5 for the 91's.



Removing this from the column did not strain the 20-ton press in the least. I think I could have done it by hand without the press.



Out of the press.



Compare the extension of the switch actuating rod key in and key out.



The casting is 3.5mm thick where the pins are. The knurled pins are 3mm in diameter and 5.5mm long.



My approach to digging out the pins is ugly. I'm thinking of tree stumps. I would not know how a drill could be useful here because the pins are hard, the surrounding casting and cylinder they lock in soft, and I may want something left to hold the pins for reassembly.







The cylinder slid out of the casting easily with a light tap.







Estension??



This is currently a deterrent to investigating the cylinder innards. I will check to see if I have another 1986 or later version to sacrifice to curiosity, because I assume the older cylinders are different since the valet key design done for '86.



This and the following pics show the steering lock. Opened out of curiosity.












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