Headlight Electrical Fault

[thelostscott]

So both my main lamps on my headlights have just stopped working within a couple days of each other and I'm just wondering if this is an issue others have come across?

Side lamps and full beam work fine, main lamp bulbs themselves are fine. My thoughts at the moment are an earthing issue, but it's really just an assumption.

Any help is appreciated.

Thanks

 

[SteveS]

So both my main lamps on my headlights have just stopped working within a couple days of each other and I'm just wondering if this is an issue others have come across?

Side lamps and full beam work fine, main lamp bulbs themselves are fine. My thoughts at the moment are an earthing issue, but it's really just an assumption.

Any help is appreciated.

Thanks

Download the EWD to check whether there is a common earth wire serving both lights.....given that they gave up at slightly different times it does not sound like a common fault/mode otherwise they would have both packed up at the same time. The EWD will tell you if the main beam and dipped lights have separate earth wires. Could just be a coincidence.

 

[thelostscott]

So gave it all a pretty good once over and still can't find a solution... Replaced all the bulbs, checked all the fuses, found & checked all the power and earths and no improvement? One thing I do find odd though is that the main beam lights come on still when I flash high-beams? Which leads to another found issue, I can't get any high-beam on full time, only on flash??

Could the issue be the indicator stalk?

 

[StarCruiser]

Sounds plausible. The thing to do is check for voltage across switches and relays etc. Not easy in practice but tracing the wiring helps. It sounds to me like something got hot and melted/deformed deteriorating the connection. Have you checked the relays or is it one of these horrible electronic boxes?

 

[thelostscott]

So after many hours trying to fix this damn thing I gave up and took it into Toyota

They spent about 6 hours on it trying figure out what the issue was by following the loom and it turns out to be......

A faulty rear fog light switch???

According to the wiring diagram, the main beam power loops through this and because it was faulty it had stopped everything right there.

I've never heard of that one before and neither had the Toyota "Master Technician", but thought I had better report in in-case someone else here ever has this problem.

Thanks Star & Steve for the advice