Ignition and Main-Beam Tell-tales

Ignition   Main-beam

Ignition Warning: All ignition warning lights have two connections - neither earthed - as at various times either side of the bulb can have a connection to 12v. CB cars use an MES E10 screw-fitting bulb (GLB987) in a holder that pushes into a plastic tube mounted on the back of the tach:

The back of a 68 to 72 tach with the plastic tube for the ignition warning light on the right and the hole for the claw-type illumination bulb holder on the left: (Peter Mayo)

Padded dash, all V8, RB 4-cylinder - a lens carrier pushes into the front of the binnacle panel:

As originally fitted they are held in place with retaining washer BHA5125 (arrowed) which makes them difficult to remove with the dash in-situ, however the bulb and bulb-holder (13H1925 bayonet, 13H1926 push-in) just push in to the lens carrier:

Indicators and main beam are the same except for the wire colours:

They take a BA7S (GLB281) bulb i.e. bayonet fitting. However unlike bayonet bulbs with pins they do not push, twist and lock, if you turn them through more than 90 degrees they come out again:

V8 and early RB ignition warning light is relatively easy to get at, but not main-beam as the centre console is in the way. For 77 and later with the plastic dash the main beam and right-hand indicator are actually the easiest as the tach is relatively easy to remove, it is the others that are more difficult. These dashboards have their own sub-harness so were fully assembled on the bench, the sub-harness being plugged into the main harness when the dash was fitted to the car.

The original style BCA4780 on the left is available from Rimmers, whereas Moss Europe only have the after-market alternative on the right:

The original has the bulb holder as a simple push-fit into the lens carrier, whereas the after-market type may click into place and need prising out - tricky behind the dash. These bulb holders have two connections as they push into a plastic lens carrier and hence need a wired earth: (Datch.fr)

Main-beam: CB tell-tales are basically the same except the bulb holders only have one wire (similar to the illumination bulb holders) as they pick up an earth from the speedo case. Here the insulated tube holder has copper strips up the outside, with at least one turned over to go down inside the tube as on the left here, and the bulb holder makes contact with it as it is pushed in. Whether the one on the right has broken off, or both are not provided for some reason, I don't know without checking the speedo in the Bee. It looks like tachs have the same copper strips externally, but they do not go down inside:

RB AAU3858. This is difficult to get at on V8 and early RB as being on the left the centre console is in the way. Easier on 77 and later as the lamp is on the other side and it's relatively easy to remove the tach to access it, and the right-hand indicator tell-tale. It's the ignition and left-hand indicator that are more difficult:

This is the ignition warning light, indicators and main beam are the same except for the wire colours:

They take a BA7S (GLB281) bulb i.e. bayonet fitting. However unlike bayonet bulbs with pins they do not push, twist and lock, if you turn them through more than 90 degrees they come out again:

77 and later dashboards have their own sub-harness so were fully assembled on the bench, the sub-harness being plugged into the main harness when the dash was fitted to the car.

The original style on the left are available from Rimmers, with an after-market type from Moss Europe. Again the bulb holders have two wires - one of them an earth - as they push into a plastic carrier: