Brake Light Warning

[yank30265]

My warning comes on the dash sometimes for the brake light turn or runnig but then sometimes it goes out; i cant find a bad bulb back there any suggestions?

[1990LS400]

Which brake warning light? A warning light can be triggered if the brake fluid is low or the switch in the brake fluid reservoir fails or the float gets saturated and no longer floats. The parking brake warning light can be triggered if the parking brake pedal doesn't retract up all the way when released with the pull handle. I sometimes had to clean the parking brake pedal lever mechanism on the 90 LS I had to get it to retract. Not sure if it was the right thing to do but spraying with clear silicon spray seemed to help too. Sometimes I just used my left foot to nudge the parking brake pedal up enough to turn off the warning light. The parking brake pedal lever can get a little sticky when it's cold -- been cold in Georgia lately? Ha!

Or maybe it is a bulb with a loose filament or a bad ground connection -- also can exhibit problems when it gets cold and metal shrinks slightly.

[eatingupblacktop]

Trunk harness?

[1990LS400]

Trunk harness?

Problems with broken wires at the drivers side trunk hinge are also sometimes accompanied by the Reverse gear indicator light in the gauge cluster flashing on and off while the car is in Drive, weird transmission shifting and other wacky symptoms.

Good call, EUBT!

[yank30265]

Trunk harness?

Problems with broken wires at the drivers side trunk hinge are also sometimes accompanied by the Reverse gear indicator light in the gauge cluster flashing on and off while the car is in Drive, weird transmission shifting and other wacky symptoms.

Good call, EUBT!

i checked the trunk harness and didnt find any broken wires; I was wondering if its the lamp failure switch secured to the rear seat on the left side of trunk(drivers). Brake fluid looks full; Where would the wires b broken; i followed them as far as I could; mainly loooked where they bend. Last time the light came on I just got the car and didnt know about its electriucal history; so I cheked and found a blown bulb. The bulbs in the rear werewnt 1157 like book called for but cthey were a 2057 or something sililar. i was told dont worry about that they just blow out faster. As they blow I replace w/1157's

[gabep]

You may find a broken wire in the plastic shield in the trunk. I found that in my Camry.

[1990LS400]

The bulbs in the rear werewnt 1157 like book called for but cthey were a 2057 or something sililar. i was told dont worry about that they just blow out faster. As they blow I replace w/1157's

It would be good to get all the bulbs replaced with the right types -- that could be triggering the warning light. It's surprising how blackened the bulb glass can get after a few years.

Wires in the harness at the left trunk hinge usually break or crack where they bend -- unwrap the tape from the harness and closely inspect each wire .... wiggle each wire to make sure the wire core inside the insulation hasn't cracked ... sometimes the wire core can crack but the insulation is still intact. I'm still guessing it is a bulb problem or perhaps a ground problem in the trunk. It's rare for the lamp failure module you mentioned to fail.

It once took me a couple of years to find why the bulb failure warning light on the dash kept lighting up even though all the bulbs were OK -- turned out to be a loose connector in a trailer light harness that a hitch company had installed years earlier.

[curiousB]

It would be good to get all the bulbs replaced with the right types -- that could be triggering the warning light. It's surprising how blackened the bulb glass can get after a few years.

This is very true. The circuit for detecting lamps out is based on current. When you go to an auto store now a days for every bulb size there is a seeming endless version of halogen, non halogen, tinted, clear, low power, high power, high efficiency, and so on.. Regardless the circuit expects to see a bulb that use the same current as the original design otherwise else the detect circuit gets confused.