Headlamp Not Working, Side & Main Beam O.K.

[Scylla]

As the title says - front left lamp will only work in sidelamp or main/high beam mode, the regular headlamp (is it called dipped)? doesn't work. Tried replacing the bulb. There's also a slight pulsing effect going on, not repeated in right hand lamp. I found the fuse which, when removed, cuts the light out altogether, so I also tried replacing that, but apart from that I'm a bit stuck.

Bus had a new alternator fitted just before I bought it four months ago.

Thanks all

Damian

[dtrumbo]

... the regular headlamp (is it called dipped)? doesn't work.

Hi Damian, I think you mean "dimmed". If I understand you correctly, the left "low beam" doesn't work properly but pulses randomly. Since you've replaced the entire lamp with the same result, the problem is most likely to be a dirty connection. Take a close look at the socket that plugs onto the lamp. Make sure all of the individual contacts in the plastic plug are clean and free of corrosion. A tiny screw driver can be used to scrape away any corrosion until it's clean and shiny. A spray can of electrical contact cleaner helps also.

It the lamp still behaves erratically after that, go back to the fuse you removed and make sure the connections in the fuse box and the fuse itself are all clean and shiny as well.

Since the high-beam works, that means the ground connection for the entire lamp is good. Since the right-side lamp works correctly, that rules out the dimmer relay.

Let us know what you find.

[Scylla]

Hi Dick - thanks for such a quick response, will do as you suggest and let you know. By the way - is the fuse I removed the only one I need concern myself with, or are there others in the box which could also be responsible?

Cheers

Damian

[Amskeptic]

Hi Dick - thanks for such a quick response, will do as you suggest and let you know. By the way - is the fuse I removed the only one I need concern myself with, or are there others in the box which could also be responsible?

Cheers

Damian

Safety required that all headlamps be fused separately, so no, you have just one for the low beam left headlamp filament. Check wiring from dimmer ("dip" in Merrye Olde England) switch. Each beam set 56a and 56b from switch has a buss bar in the fuse box where the separate filaments have their own fused output.
Colin

[Scylla]

Problem solved - I located the fuse that controls the dipped/dimmed/whatever light and took it out, polished up the contacts and when I put it back in, I had an operational headlight again! Most satisfying.

Thanks all for the responses. Just gotta sort out the leak in the front indicator now...

Damian