Many PV/1800/120 owners have contacted me with the problem of an ignition key broken off in the lock barrel. This is a common problem on these models built prior to 1968/69 when Volvo changed the design to a Steering/Ignition lock.
The removal of the barrel on pre ‘68/69 1800/120 and also PV models is the same but is not described in any of the Volvo Workshop Manuals, The barrel itself is fitted into the ignition switch and sandwiches the dash as shown in Fig: 1. Removal of the barrel is as follows:
The Ignition Switch itself is secured to the lower edge of the dash by two Philips screws No:21 on Fig: 2. These should be removed, thus allowing the switch to be rotated as required.
Attention should now be paid to the switch itself, which can be viewed by looking up the rear of the dash. I would suggest that moving the driver’s seat back as far as possible or removal should help with access. Using a torch and looking at the front end of the switch near where it goes through the dash, you will be able to view the locking device as shown in Fig; 2 – A Round Pin in a hole around the 10 o’clock position. In order to remove the barrel this pin must be depressed, thus allowing the barrel to be withdrawn from the front of the dash.
Depressing the pin is not straightforward as it can only be depressed with the Ignition Key in one position. In other positions, it is locked and cannot be depressed. Viewing from the front of the barrel, see Fig; 3 key positions are shown –
POSITION 1                     STARTER MOTOR
POSITION 2                     IGNITION ON
POSITION 3                     OFF POSITION

It is important that you establish which position the key is in. In order to depress the pin successfully the key MUST be in a position midway between POSITIONS 2 & 3 e.g. ‘IGNITION ON and ‘OFF POSITION’. (It may help at this stage to have an assistant to set the position of the key to with draw the barrel). Once this has been achieved the pin should be depressed using a piece of bent wire or a screwdriver. The barrel should then slide out of the lock tube from the dash.
Replacement of the barrel is an easy operation, in that the barrel is pushed through the dash into the lock tube until the pin locks into the locking hole. The key again will need to be in the correct position as above but one the pin locks into the securing hole the key can be withdrawn. The two screws from the lower dash should be replaced to complete the exercise.
If the key breaks again I would suggest that the switch may require lubricating (which can be done with barrel removed) or possibly a new barrel is required, which are still available new.
For members/owners of the PV/1800/120 who are not familiar with the ignition system on these models, the ignition coil and the Ignition switch are one unit and are connected via an armoured cable which contains the low tension lead to the coil from the switch (an excellent anti-burglar device) Should either of these items require replacement, the ignition switch must be removed as described above.
NOTE: Should you be unable to turn the key to the correct position, the barrel may have to be drilled out.

Reprinted from Issue No: 45 of the Volvo Enthusiasts Club Magazine