W124 sidelights

[brucemillar]

I am not sure if this is normal or not?

On my 124, with the sidelights on, the headlight bulbs (both sides) also come on very dimly. Replaced all bulbs with brand new ones as part of a general tidy up and noticed this. So I put the old bulbs back in and get the same symptoms. With the headlights on all seems OK.

Is this normal? If not, any clues.

Regards

Bruce

 

[bolide]

Normally that means there's a bad earth on one of the lamp holders. The W124 has a plug & socket arrangement so I am not sure how you'd arrive at a bad earth for both sidelights at the same time. But I'd unplug one headlight, test the other & proceed from there

You haven't fitted an incorrect bulb have you? Some cars (not W124s) use twin-filament bulbs with two pins at the base

Nick Froome
the independent Mercedes Estate specialists

 

[brucemillar]

Nick

Incorrect bulbs is a good possibility. I stuck in some H7's that I had in my garage. I have no idea what the previous owner did. Is there any obvious way to check if H7's could be dual fillament/

 

[bolide]

W124 needs H4

Nick Froome
the independent Mercedes Estate specialists

 

[brucemillar]

Nick

I meant H4's. Bit too much much Vino Collapso.

 

[coalville126]

It might be the dim-dip feature as fitted to many cars sold in the UK from the mid 1980s till the end of the decade. Dip headlamp bulbs illuminated a half brightness, but only with the ignition on or engine running when the sidelights are switched on. It was to prevent drivers driving with just the side lights on.

 

[brucemillar]

This sounds good. It is a 1985 car so this could well be what I am getting.

Thank you.

 

[Tiff]

It might be the dim-dip feature as fitted to many cars sold in the UK from the mid 1980s till the end of the decade. Dip headlamp bulbs illuminated a half brightness, but only with the ignition on or engine running when the sidelights are switched on. It was to prevent drivers driving with just the side lights on.

Yup, was going to be law in the UK around this time, but never went through- there should be a small exposed coil on the inner wing somewhere which was the resistor for the dipped beam- you can disable it if it annoys you.