Happy Thanksgiving!I own a 2003 RX300 which never had given me any trouble so far. I had another driver telling me one day that I have no brake lights what so over. I thought it is just bulbs so I replaced the third light bulb and still no brake light.

I did some search and discovered about the brake light module which located within the panel at trunk on the driver side as per this video:


It says that I could try a jumper solution at 2:48 which I did.

This is when things get interesting. After I tried this, the brake light did come on when I stepped on the brake but I lost other lights (turn indicators, reverse and rear lights).

At the same time I also lost power windows and the heat.

I tried soldering every component on the brake light module, thinking it might be bad connections but still I have the same problem (no heat, no power window, no rear lights except brake).

The power windows make no sound what so ever, so my guess is there is no power flows through the system at all. Nothing also happened at the display when I pressed the climate control button. The display works as the radio and CD is on.

My guess is this was caused by me jumping the connectors at the brake light module?

I checked the fuses with multimeter on the left side of the steering wheel inside the car and they all show continuity. Not sure if they are other way to check the fuses or maybe there are other fuses I should check?

I can't be driving this car at the moment without heat (it is -20 here) as well no lights are working at the moment.

I appreciate very much any help I can get with this!

Thanks

 

I would disconnect the battery, wait a few minutes, and then reconnect (1st remove the jumper wire if you have not already). Then see if your heat and power windows work. Also, I found the following information in a post about the lamp failure module and/or no brake lights back when I was researching the forum. I put it in a Word document in case I needed it in the future:
My Lexus RX 300 brakes lights wouldn't come on when I pressed the brake pedal. Checked the fuse and it was okay. Read online to check the light failure sensor in the back luggage compartment on the driver's side. Took a while to figure out how to remove the trim. Held in mostly with plastic push in plugs that you have to pry out. Found the sensor box, detached it and removed the connector. Read online where you can bypass the sensor box for the rear brake lights (see below).

"Find a green\white wire on pin 7, Find a Green\Yellow wire on pin 1, Find a Green\Red wire on pin 2. Cut these 3 wires and connect them together."

I cut the three wires a little way back from the connector so in case I had to I could splice them back together. Twisted the three wires together, plugged the connector back into the sensor box and tested the brake lights. Brake lights all work. No cost solution and out only a little time. Put a wire nut on the twisted wires and wrapped up with black electrical tape.


DON"T cut wires and/or fool with electrical stuff on any car without disconnecting the battery FIRST! So for you, if you do this override thing, you'll end up disconnecting the battery twice - once to see if you can get the windows and heat to work, and again to do the override.
Last but not least, I'm not a certified mechanic (and I don't play one on TV) so....

 

Thanks for your reply! I did disconnect the battery first and the window and the heat still didn't work.

So I went back to the fuse (to the left of the steering wheel) and check every piece of it properly with a fuse tester. Lo and behold I got three burnt fuses. This happened when I was jumping different wires on the brake light module. The ones burnt were for "Gauge, Rear, and Cig". I replaced these and everything worked, including the rear lights and the brake lights.

I would say if the same thing ever happened to me again, I would take the brake light module out. Check every solder piece and resolder the weak ones before jumping anything. And as you said above, I should disconnect the battery first!

 

Awesome! Thanks for letting us know what you did and how it turned out.

 

My brake lights were also not working, so I tried this fix, and it worked!

What I'm wondering is what is the purpose of that sensor? What functionality have I bypassed?

 

I think you bypassed the warning light on the dash that tells you when a bulb is burned out.