can't get brake lights to light - Toyota Yaris Forums

gotno · 02-23-2013, 05:05 PM

hi all, trying to fix a friend's stop lights.

the two lower brake lights are out. the high mounted brake light is lighting like normal.

i have checked the stop fuse with a multimeter, and it's good. i tested the stop light switch and pins 3&4 were giving a funny reading, so i replaced the switch. still no lights. replaced both bulbs, still no good. checked power to the socket by unplugging the 6 pin (J3/J4) connector and testing pins 5&6. 0v with the brake pedal out and a solid 12v with the brake pedal pressed, but the bulbs won't light.

before i replaced the bulbs, i tested the ones installed by removing them and hooking them straight to a 9v battery, and they lit just find. if i try to connect the same power to pins 5&6 of the terminal with the bulb in the socket, the bulb won't light.

i'm clearly not understanding something about the circuitry here. i've got twelve volts going to the terminal on both sides, but the bulbs won't light. what do the other three pins on that connector do? what am i missing?

thanks!

CTScott · 02-23-2013, 05:48 PM

It sounds like you have the 12 volt side, but not the ground side. Try checking continuity between the bulb socket's ground terminal and a chassis ground point.

gotno · 02-23-2013, 08:07 PM

ha. my bad. i was checking the backup light bulbs, not the stop bulbs. feel like a moron. thanks for the help!

02-23-2013, 05:05 PM	#1
gotno reason to quit Drives: yaris Join Date: Feb 2013 Location: syracuse, ut Posts: 2	can't get brake lights to light hi all, trying to fix a friend's stop lights. the two lower brake lights are out. the high mounted brake light is lighting like normal. i have checked the stop fuse with a multimeter, and it's good. i tested the stop light switch and pins 3&4 were giving a funny reading, so i replaced the switch. still no lights. replaced both bulbs, still no good. checked power to the socket by unplugging the 6 pin (J3/J4) connector and testing pins 5&6. 0v with the brake pedal out and a solid 12v with the brake pedal pressed, but the bulbs won't light. before i replaced the bulbs, i tested the ones installed by removing them and hooking them straight to a 9v battery, and they lit just find. if i try to connect the same power to pins 5&6 of the terminal with the bulb in the socket, the bulb won't light. i'm clearly not understanding something about the circuitry here. i've got twelve volts going to the terminal on both sides, but the bulbs won't light. what do the other three pins on that connector do? what am i missing? thanks!

02-23-2013, 05:48 PM	#2
CTScott ULTIMATE View User's Garage Drives: 09 5dr LB, 2x 08 3dr LB Join Date: Oct 2008 Location: USA, CT Posts: 13,460	It sounds like you have the 12 volt side, but not the ground side. Try checking continuity between the bulb socket's ground terminal and a chassis ground point. __________________

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02-23-2013, 08:07 PM	#3
gotno reason to quit Drives: yaris Join Date: Feb 2013 Location: syracuse, ut Posts: 2	ha. my bad. i was checking the backup light bulbs, not the stop bulbs. feel like a moron. thanks for the help!