Rear lights explanation (newbie question)

[Jureb]

Very clear Jureb, and the most likely cause of your problem. Lets hope you can find an area of good metal on there you can get a good clean fix to, if not there, on another part of that ground. If not solder, maybe with pilot hole drilled and pk screw. As long as all surfaces clean, the thread of the screw biting in metal should help.
Unfortunately as seen, those with low level lights on their cruisers have found the same after time.
I had both the metal shrouds/covers rot out on my 120, and had to replace. There's just not enough protection from all the sh/t that gets slung in that direction.

Thanks for the tip. I will most likely make a pilot hole in the metal cover, crimp a little cable shoe to the ground (WB) wire and screw it to the metal cover, hopefully it will make a good connection.
The location of the tail lights is really unfortunate and really bad protection too... If I ever change the bumper tail lights I will surely drown this metal cover in a dielectric grease!

 

[Jureb]

Update:
I made a pilot hole in the metal cover, took a very short screw and made it even shorter (2-3mm length), crimped a cable shoe on the ground wire (white-black) and screwed the screw along with the wire to metal cover. I wanted to solder everything up with the metal cover so the wire would "never" fall off BUT I noticed that the damn solder wouldn't stick to the metal cover. I also tried soldering the wire on the inside of the tail light where there is no rust but the solder wouldn't stick at all. My solder wire has flux in it and it always works good, the metal surface was heated up but still I couldn't achieve the solder to stick to the surface - it's probably aluminium, which is very difficult to solder.
In the end stopped messing around with the soldering iron and put a cable tie around the metal cover and the ground wire, it shouldn't fall off so easy.

The lights are now working properly. Case closed.

 

[Tractionman]

Well done Jureb, always a result thinking outside the box. Might be an idea to protect it with anything at hand, Vaseline grease, etc

 

[Jureb]

Would vaseline or anything else remain there after the first rain? I was thinking of protecting it with silicone grease or maybe white (lithium) grease. Still trying to decide what would be better.

 

[AdventureWagon]

In a pinch I've 'soldered' to aluminium components by twisting steel or copper wire round tight then soldering the twist. Weird that Toyota used bayonet bulbs here and not the wedge base used in the body lights. Leftover parts bin stuff I'm guessing!

 

[AdventureWagon]

And I think any grease or even Vaseline would be better than nothing.

 

[Tractionman]

Jureb, Vaseline or grease just suggestions as stated, as what you had to hand. Lithium and the silicone version is still grease, or electrical grease, or the stuff off yer fish and chips. It's just to try and maintain that clean earth connection that has been the cause of your probs. As AdventureWagon says, anything better than nothing. Paint it if you like.
Your picture looks very much like steel, as per rust and section where you cleaned off. I don't think you can solder aluminium, but someone correct me if I am wrong. I think the problem might be that to solder a joint, all components need to be hot/same temperature, or it will stick to one and not the other.. The part on light and the wire are two differing thicknesses and two different materials, so heat may have been the problem. Just because the solder 'melts' is not sufficient, and of course correct flux plays a part with cleaning effect and flow, which I use in conjunction with any solder that is supposed to have it included.
Having said all that, carry on with all the fettling, it will all be worth it when everything done.

 

[Jureb]

I surely will grease it up today, most likely with the silicone grease. Vaseline is not a bad idea that's for sure, thanks for the suggestion, would use it if I didn't have silicone grease.
Solder most likely didn't stick because I probably couldn't heat everything up enough for the solder to stick - there are quite some metallic parts in the light which act like a huge heat sink and the surrounding temperature being -10° to -5°C these days doesn't really do me any favors. Might retry soldering it in a couple of months.

 

[Jureb]

I tried soldering the wire to the metal cover again. Last time I used some cheap, rubbish 30 W soldering iron and I figured I couldn't heat everything up enough. This time I used a real good 250 Watt (Weller) soldering iron station which heats up to 550 °C and again I couldn't solder the wire. I was heating up everything for minutes but no success. Maybe I will try again in the summer. I did everything I could at these weather conditions.

Cable ties and silicone grease (for protection) will have to do the job.

 

[Tractionman]

You have a decent enough soldering iron for general use, there Jureb. The metal needs to be cleaner than your picture shows, maybe you have done that since. Everything needs to be shiny metal, with no grease, using a dremel or similar for best results, with decent solder and flux. As you have found before, the weather is against you, taking heat away, and the metal is a heat sink, especially now, as cold. I realise you want to do the best job possible, but personally, as long as that screw is good and tight with a good grip, I would leave it, as it is obviously making good contact. You could rivet it for a more secure job than the screw, using a washer to cover the earth tag you put on, otherwise the rivet could pull through the eye.
As you said, if your gonna try again to solder, wait until warmer.
Thanks for update, always good to know how people get on with problems.

 

[Jureb]

I borrowed the soldering iron from work heh. I cleaned the metal as much as I could but the result wasn't really noticeable. I also tried soldering on the inside of the light - the socket where the bulb sits where everything is spotless and clean, solder wouldn't stick even there: heat sink is too big, low temperatures, aluminium? We'll see when I try again in a couple of months .

 

[diggerdave]

Soldering is like plastering. Sounds straightforward, but it's actually a dark art that can only be mastered by mystical craftsmen trained by ancient masters

 

[AdventureWagon]

It's a massive hack but in a worse case scenario like this you can solder to the light bulb terminals and base directly.

 

[Bob]

I've been there AW. I ended up drilling out the original fittings with a 25mm holes away and fitting new sealed bulb holders into the existing lamps. Cheaper than new lamps, and works just fine.

 

[AdventureWagon]

Yeah my trailer has very old fashioned festoon bulbs you never find at service stations so I keep a couple of normal bulbs with pigtails soldered to them. It's a good get out of jail free card!