1987 Toyota Camry -BRAKE (STOP) LIGHTS DO NOT LIGHT

[josiah]

Make

toyota

Model

camry

Year

1987

Miles

235,000

Engine

4 cylinder

BACKGROUND INFORMATION
Prior problem: Earlier in May the brake (stop) lights were staying on.
Solution: Early June I installed rubber cushion. (The old cushion had deteriorated and had fallen out). I'm sure you already know this, but when the brakes are released the brake switch pin presses against the cushion to turn off the brake lights. In order to plug in the cushion I first needed to remove the brake light switch; was able to do so with the help of Mobile Dan, Nickb2 and Bob428.
After cushion installation and reinstalling the switch (after testing for resistance) the brakes lights worked correctly. Car passed state inspection 2 weeks later.

CURRENT PROBLEM
8/28/21 (almost 3 months later) informed by neighbor that my brake lights were not coming on.
Using trouble shooting tips from my Toyota corp repair manual for STOP LIGHTS DO NOT LIGHT here is what I have already checked:
1) Check stop fuse. I pulled the fuse, the fuse was not burned through. Tested resistance with volt/ohm tester which showed zero resistance. Fuse ok.
2) Check brake light switch. So I removed brake light switch. The switch has 4 terminals. Tested resistance of terminal #1 to #3; and terminal #2 to #4. After cleaning light corrosion coating on terminal 3 the switch passed. Switch ok.
3) Also I checked to see if the switch needed adjustment. Visually check to see if the brake switch pin was allowed to fully extend when the brakes were pressed and the pin appears to have adequate space to extend which should turn the lights on, but they do not come on.

So I did the above and the brake lights are still not coming on.
The manual mentions check wiring and ground but no additional instructions on how this is done.

Any suggestions would be appreciated.
Thanks, Josiah

 

[billr]

Find your old thread and post a link to it (or just bump it up to current). There were some good diagrams of that goofy brake-light-switch arrangement in that old thread; save me from having to search for it.

 

[grcauto]

Agree with billr.

 

[josiah]

https://www.batauto.com/threads/remove-electrical-connector-from-brake-light-switch.15896/

Billr and grcauto,
Previous thread (email discussion) attached above. But I do not see the diagrams you mentioned.
Thanks for responding.
Any help would be appreciated.
Josiah

 

[billr]

The diagram I was looking for is in reply #20 of that old thread.

Can you easily connect the switch to the wiring, but have it not mounted? If so, do that to confirm this isn't just an adjustment problem.

If no joy with that, then we will need somebody to post the schematic for that circuit. Then, we can guide you in tracking this down with the voltmeter.

 

[grcauto]

Here's the wiring diagram. It's at D30

 

[billr]

What voltage do you have, referenced to ground, on pin 3 and pin 1 of the brake-light switch harness? Check this with KOEO and with the harness connected to the switch and disconnected, both ways. Did you try connecting the switch to the harness, unmounted?

GRC, do you have more of the wiring diagram? I would like to follow that circuit to the PCM and then on to the brake lights themselves.

 

[paulo57509]

FWIW...

I had an '87 Camry years ago. It also had a brake light problem. IIRC, no brake lights and no brake lamp failure warning light.

There is a plastic junction box/block inside the trunk (either on the back wall of the trunk or lid) where I found a loose ring terminal under a screw. Tightened it and issue went away. The screw threads into plastic so don't over tighten.

 

[grcauto]

What voltage do you have, referenced to ground, on pin 3 and pin 1 of the brake-light switch harness? Check this with KOEO and with the harness connected to the switch and disconnected, both ways. Did you try connecting the switch to the harness, unmounted?

GRC, do you have more of the wiring diagram? I would like to follow that circuit to the PCM and then on to the brake lights themselves.

Here's this.

 

[josiah]

PLease pardon the delay in responding.
Billr now the brake switch connects easily to the electrical connector. Please note that it doesn’t snap in the way it did originally because the tooth at top of connector looks a little rounded off. Likely caused when I removed it from the switch back in June; I pushed the connector out of the switch with a screwdriver. In other words, the connector doesn’t fit as tightly as it did originally. Perhaps that‘s the problem?
Billr above you asked about what voltage do I have between switch pin 1 and 3. I do not understand how to do this.
I plan to take another look tomorrow.
Thanks.

 

[josiah]

Guys,
I THINK I see the problem. The brake light switch plugs into the electrical connector. The switch has 4 terminals which match with 4 slots in the connector. However slot#3 has noticeable corrosion (note:corrosion was found on matching switch terminal#3 which I removed with extra-fine sand paper). Apparently, to turn the brake lights on current must pass from terminal/slot #1 to #3.
How do I remove corrosion inside the electrical connector slot? Is there a spray cleaner?
Thanks.

 

[grcauto]

Use a highly alkaline solution. A cup of water and a few tablespoons of baking soda will do. Soak it overnight. See how it looks. All the green death gone? It'll look dull and a bit dark but you don't want any green or white. Once it's neutralized use dielectric grease and assemble.

 

[JackC]

I like grcauto's idea. If that does not work, ( and you are sure that is the problem) you may have to replace the entire connector assy.

 

[josiah]

grcauto and JackC,
Thanks for the reply.
However I am not completely sure what I need to do? Right now I am on my back looking up at the connector(at the highest point above). I assume in order to follow your instructions above I will need to unplug the assembly (connector+wires)? If my assumption is right then how do I unplug it? Do I start at the connector and follow the wires to some starting position and unplug it there? If I could do this, that would be good because then it would be in my hand, so following your instructions would be easy.
Also I appreciate the dielectric grease advice.

Thanks.

 

[grcauto]

Oh! The multiplug connector has corrosion. Yikes! That means you'll either need to remove the multiplug or get at it with a pick and pick the green death off it.