Don't like the adverts?  Click here to remove them

Weird Electrical Gremlin -- Brake Light Doesn't Work When Headlights Are On

stuzbot

Well-Known Member
Joined
Jan 20, 2021
Messages
469
As per the title. All brake lights working fine normally But, when I put the headlights on, one of the brake lights stops working.

Before I get out the multimeter and start scratching my head; does anyone have any ideas as to what could be causing this odd electrical gremlin?
 
First port of call is always the tow socket and rear bumper lights .
 
Hmmm... I didn't think the bumper lights were even connected on these. Towbar socket could be a likely culprit I suppose, as it would take a feed off the brake light circuit so it could activate the brake lights on whatever you were towing.

For all I know, this problem could have existed since I bought the truck. I've hardly done any night time driving in it and not had it long enough to have used it in the 'nights drawing in' part of the year before now.
 
Most of the upper rear lights are dummies , change in the law made Toyota add the bumper lights , a truly professional bodge if you like but the bloody things are connected to everything and can light up your dash like Blackpool illuminations when they start to rust out .
 
Stuz, you could check underneath to see if some bodger has used scotchlok connectors on towbar wiring to check, open the black 12n socket and look inside, any corrosion will be evident and even if not, allow you to do test with multimeter. There is also a simple tow socket tester for about a tenner, maybe not justified for a 'one off'. Sounds like you will need an assistant for electrical testing with brake pedal pressed, - or a brick !!
 
Iv had same issues with my old Colorado, I think Shayne and Tractionman have covered it..... My cure was Towbar electrics sorted, and all was well... Good luck Mate
 
Don't like the adverts?  Click here to remove them
Back
Top