Alfa Romeo Forum banner

1 - 13 of 13 Posts

·
Registered
Joined
·
569 Posts
Discussion Starter #1
Hi

The passenger side dipped beam headlight hasnt worked since iv had the car. All other lights work fine.

Tested the wiring and there is current there, but when i plug the bulb in, nothing! Power seems to go also.
I have tested the output as i only have a basic tester, but could there not be enough power running through?
Why only dipped and not full beam?
And why only one side?

uhh. :confused::rolleyes:

Any ideas people?

Many thanks
Kev
 

·
Regional Support, For Lincolnshire - AOL
Joined
·
16,322 Posts
All I can think of, in general terms as I'm no expert on these cars, is that you have a very poor/corroded contact somewhere in the wiring to the Dipped Beam.

This would give the symptoms you have, apparently full volts when not under load and then dropping to virtually nothing when you switch on. This is often due to the poor contact resistance going high when it tries to carry the current.

Either start tracing the wiring back ( after ensuring that the actual contacts, including the Earth, on the Lamp Unit itself are OK ) or wait and see if anyone else has had a similar problem and knows where exactly the problematic contact/junction may be.

Just as well the nights are light !!!!
 

·
Registered
Joined
·
569 Posts
Discussion Starter #3
All contact and wiring are fine bulb end.. But looked like id have to take the wheel off to trace it back..

cheers
 

·
Registered
Joined
·
5,213 Posts
I'd be suspecting the bulb holders, they are not the best quality items and are clearly upwards of forty years old now. Can you get it lit by waggling the bulb about?.

Bad earths can cause strange problems too, try checking and remaking all those.
 

·
Registered
Joined
·
569 Posts
Discussion Starter #7
Yep. Tried a wiggle but nothing.
I have traced the earth back and it does look pretty corroded and gunked up.
I need to take the wheel off to get to it properly though
 

·
Registered
Joined
·
5,213 Posts
I'd try the earth then, you will need to take the splash guard out too. Not the nicest job that, the screws are usually rusted up and round off.

Just a thought though, you have got the right type of bulb haven't you? it's not a single filament one instead is it?, have you tried swapping it for the other side?
 

·
Registered
Joined
·
1,597 Posts
Assuming that it is a dual filament bulb and one of the filaments works then the ground could be OK - if it is like the Spider headlights it is a common ground for both. But, as Mitch has said, it is always worth cleaning the grounds anyway as they do get corroded.

I agree with Nige, it sounds like the wire for the dipped beam that is the problem. You could test it by disconnecting the wire from the back of the bulb holder and then running a power feed from anywhere to that connector e.g. stick one end of a wire into the female connector for the high beam and the other end to the male connector for the low on the bulb holder. Turn on high beam and see what happens.

I had this problem with a side light - multimeter showed 12 volts, bulb was good when put in the other side but it wouldn't even glow a little in the problem side. I eventually found a broken wire.

This is a great read, which explains how you can have voltage showing on a multimeter but no light Voltage Drop Testing
 
1 - 13 of 13 Posts
Top