Technical Problem with Lights Help!

[oldskoolmk1unoturbo]

ok as listed on my mot failure sheet i seem to have a problem with my rear lights, basically when the side lights, dipped beam or main beam is on, they are diming low when the click comes on with the indictors.

i have swopped the entire rear lights on both sides with some spare ones i had and i have replaced all the bulbs too and still no luck, I'm thinking its a bad earth but i dont know where to start.

check out the videos to see what i mean,

Thanks.

Mark.

http://www.youtube.com/watch?v=H8TzY69A6ww

http://www.youtube.com/watch?v=oZ-HG7IVqqw

 

[Jai]

after numerous swaps, i found my problems were all in the crappy connectors, from the loom to the base plate of the rear lamps, i take it those are ok though?

 

[circolo]

I'm with Jai on this one.

I had no end of issues with my rear lights later in the cars life. With dimming lamps, indicators not working, brake lights suddenly not lighting, etc, etc.

In the end I took the complete light assembly off the car, thorough cleaned up the spade type terminal, with all the connections on, and then renewed as best the connector terminal on the car. It almost fixed the problem.

So I then cleaned (and sanded off where neccessary) the actual bulb holders in the light assembly, as the metal had weathered, and this was causing poor conductivity. I even replaced some of the bulbs, as they had become so tarnished on there metal connections, it was easier to buy fresh clean bulbs, and fit them to the cleaned up bulb holders.

Job done!

I also cleaned up the front spade connector unit under and near to the battery, as this is your earthing point for the front lights.

Incidentally if it's a load issue, (ie that when you turn more electrical components on, other components don't have enough power, or other lights dim, etc), it could be a battery or alternator fault. But I'd go through the above first before looking at this possibility.

 

[oldskoolmk1unoturbo]

it isnt a load issue, where is the earth for the lights does anyone know?

 

[Jai]

theres one under the nearside headlight, real pig to get to, i think about 7-8 bits connect into it, usually rusted and corroded...

 

[oldskoolmk1unoturbo]

just had a go at cleaning the two earths up at the front, hopefully its done the trick but i cant check cause i think i left the interior light on and the battery is dead :-(

gonna give it a overnight charge and start again tomorrow

 

[alexGS]

Hi oldskool,

Just a quick reply sorry but the earth for the rear lights is at a 13mm bolt on the rear panel - the bolt is accessible from inside the boot. As you're looking down at the spare wheel, it's on your left. Perhaps measure between here and the bulb holders with a resistance meter, really you only want 0.2-0.5 Ohms. Maybe one of the earth wires running across the back of the boot has been broken?

I agree with Circolo in that the connectors are usually the cause of these problems. You probably need to remove the terminals from the car's plugs, clean them with a wire brush, and give them a tweak with pliers to ensure they fit tightly onto the galvanised-steel pins on the light unit. Maybe pack the plug with Vaseline afterwards to keep moisture out.

I use Duzall soldering flux (green squeeze-bottle) and an 80W electric soldering iron to solder all the bulb holders onto the circuit-board base. I haven't had any earthing problems since this.

Cheers,
-Alex