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MG MGB Technical - Tail light problem

1980 MG-LE,

I have a problem with the rear lights not being on when the headlights are on. I get brake lights but no rear driving lights.

Fuses are good, bulbs are good.
Any suggestions???

Thanks,
Vincent
Vincent

Vincent -

Do the tail lights work when turned on by the switch, without the head lights? (silly question perhaps)

Get your wiring diagram out -- and identify what wires are for. Check all bullet connectors, clean or replace them. Find the nblack ground wires and make sure they are making a good contact with the car body.

Then also check the lamp assembly -- the sockets in particular -- rub a course grade of steel wool in the sockets, the terminals that make contact with the bulb, and too the grounding wire from the tail light assembly.

This is just one of the many 'It'll take longer to fine the problem than to fix it'.

Oh yeah, check the connection at the switch, it might do you well to disconnect the battery ground cable during this hide and seek, relying on a multi-meter.

glg
glg

Hi Vincent.

We need some more clues !.
Please try all combinations of lights on / off (including the front sidelights and indicators / hazards) and tell us about any that are not working correctly.

Don
Don

Referring to the late model US market wiring diagrams, the top fuses provide power to the red wires, which power only the front/rear "park" and marker lamps. The top fuse powers the left side, and the second fuse powers the right. Turn signals and brake lamps are powered from the green wires, off the third fuse.

Based on the above, your problem doesn't make sense, unless someone has rewired your car, the rear park lamp sockets are corroded, or your lamps are burned out.

Turn on the lamps, and check for power between the sockets and ground (after verifying on both sides of both fuses). If there's power...well, you've either got a "special" problem, or your lamps are no good.
Fred Doyen

This seems to point to the light switch failing to remake the side/tail circuit when switched to headlights. What do the front sidelights do when headlights are on? Are they common with the taillights?
S Best

This thread was discussed on 26/07/2005

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