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Discussion Starter · #1 ·
The orange "lights" warning light on the dash came on and all of my
brake lights even the 3rd brake light in the window suddenly stopped
working. Tail lights and all others work. What would be the likely
cause of this? Brake pedal switch gone bad? How can I test it? I
don't see a brake lights fuse under the hood... is it under the dash?
 
G

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Discussion Starter · #2 ·
"Chris" <[email protected]> wrote in message
news:[email protected]
> The orange "lights" warning light on the dash came on and all of my
> brake lights even the 3rd brake light in the window suddenly stopped
> working. Tail lights and all others work. What would be the likely
> cause of this? Brake pedal switch gone bad? How can I test it? I
> don't see a brake lights fuse under the hood... is it under the dash?
>


The likely cause of the problem is a corroded or loose ground somewhere. A
wiring diagram would help trace the ground locations so you can check, but
start in the trunk.

The brake pedal switch is easy to test. Unplug the connector and check for
continuity with a multimeter or continuity tester when depressing the
plunger on the switch.

There is nowhither fuse box under the dash on the driver's side.
--
Ray O
correct the return address punctuation to reply
 
G

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Discussion Starter · #3 ·
I will try to get a wiring diagram. There was a ground wire coming
loose on the driver side brake light and I fixed it (again). That
problem started a few years ago due to a loose ground screw at the bulb
connector, which melted the plastic around the screw. In the past it
didn't cause all brake lights to stop working, just the one bad side.
All of the trunk and 3rd brake light wiring looks good now and I
believe this is a new problem since it affects all brake lights. I
searched the group for answers and I think it might be the switch,
relay, or some electrical control box. The 20 amp stop light fuse
under the driver dash looks good. I found the pedal switch and it is
way up near the top of the dash and very difficult to access... I was
able to unplug the connector but I'm not sure if I can test with a
multimeter without removing the switch. Each time I press the pedal I
hear a solid click coming from inside the center console, near the auto
transmission shifter. I think it's the control that unlocks the
shifter when the brake pedal is pressed. Since it activates does this
indicate that the pedal switch is working? How can I test the brake
relay? I don't know where it is located. I see some fuses and relays
under the passenger side dash near the heat/AC fan. Engine is 4 cyl
with cruise control if it helps.
 
G

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Discussion Starter · #4 ·
"Chris" <[email protected]> wrote in message
news:[email protected]
>I will try to get a wiring diagram. There was a ground wire coming
> loose on the driver side brake light and I fixed it (again). That
> problem started a few years ago due to a loose ground screw at the bulb
> connector, which melted the plastic around the screw. In the past it
> didn't cause all brake lights to stop working, just the one bad side.
> All of the trunk and 3rd brake light wiring looks good now and I
> believe this is a new problem since it affects all brake lights. I
> searched the group for answers and I think it might be the switch,
> relay, or some electrical control box.


I still think you have a bad or loose ground somewhere. First check if you
have 12 volts coming into the brake light assemblies. If there is, then a
bad ground is the culprit and you don't have to mess with fuses, relays,
etc.

If you don't have 12 volts, then check the fuse with a meter - not visually.

The 20 amp stop light fuse
> under the driver dash looks good. I found the pedal switch and it is
> way up near the top of the dash and very difficult to access... I was
> able to unplug the connector but I'm not sure if I can test with a
> multimeter without removing the switch. Each time I press the pedal I
> hear a solid click coming from inside the center console, near the auto
> transmission shifter. I think it's the control that unlocks the
> shifter when the brake pedal is pressed. Since it activates does this
> indicate that the pedal switch is working?


The brake light switch is probably working if the shift lock interlock is
working.

How can I test the brake
> relay? I don't know where it is located. I see some fuses and relays
> under the passenger side dash near the heat/AC fan. Engine is 4 cyl
> with cruise control if it helps.


I'm not sure that there is a brake light relay, but to check any relay,
check if the power switches on and off with relay activation.
--
Ray O
correct the return address punctuation to reply
 
G

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Discussion Starter · #5 ·
I didn't get a voltage reading at either brake light assembly connector
except 0.1 at one lead on each side (driver and passenger). The fuse
is good and I inserted a new spare just to make sure. I didn't find
any other loose grounds.

A few older posts mentioned a yellow "lamp failure sensor" box in the
trunk near the top of the driver's side wall. I removed and opened it
up and the circuit board looks good (no burned marks). Puzzled, I did
a little more searching and found more info in this thread:

http://www.automotiveforums.com/vbulletin/t80545.html

Check out posts #23 by decible and #32 by G.I.JER. My circuit board
has the exact same problem shown in the photos. The soldered
connection at pin #12 (looking at soldered side of board) has gone bad
(appears to have melted just enough to be slightly disconnected or
shorted). It's small and barely noticeable and since there are no
other clues such as burn marks, I didn't even see it until I reviewed
these photos and inspected the board a 2nd time. To test I held a
jumper wire between the solder on the board and the wire going to it
(from a tiny white diode or resistor located just below the connector),
and this made all 5 brake lights work. I resoldered the connection and
it works fine. I'm guessing the problem was caused by the loose ground
wire on the brake lamp socket causing the board connection to heat up,
which I've now fixed more permanently (all it takes is for this screw
to get slightly loose from normal vibration to create enough heat to
melt the plastic around the screw). I'm so glad I didn't have to
replace the pedal switch! Thanks for your help!

By the way one of the best features of 87-91 generation Camrys is the 4
big tail/brake lights stretched across the entire trunk except the
license plate. Newer models have fewer or smaller lights so they are
harder to see and might be more prone to rear collisions. I especially
dislike the narrow 97-01 generation lights, which look like they are
falling asleep. The current generation is better.
 
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