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

josiah

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billr and Mobile D,
Plan to check voltage by tomorrow.
Thanks, Joe
 

grcauto

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OK, since the tail/marker lights work, then almost surely the power and ground to the YEL module are OK.

Read voltage at pin 1 of the module. If that goes high (12V) when pin 7 has 12V, then wiring between the module and the brake lights is bad. If pin 1 does not go high, then the module is bad.
What do we get it it's good?
 

billr

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I don't understand that. What are you referring to by "it", and what result or condition do you consider to be "good"?
 

Mobile Dan

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Green/white wire (pin 7) has power (12v) when you step on the brake pedal. If you supply 12V to Green/red wire (pin 1), the brake bulbs should illuminate. If you cut those two wires (at a point about 2 inches from the module connector) and then connect those two wires together....I'm thinking the brake bulbs are going to illuminate when you step on the brake pedal. The module connector needs to stay connected to module so that the taillamps will work.
 

josiah

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Billr, Mobile Dan, and Grcauto,
Please pardon delay.
Did voltage test.
1) Jumpered brake light switch harness(connector) slot#1 to #3. Voltage reading at light failed sensor (module) pin#1(gen-red wire) is 0 (zero).
2) Same test as above but instead tested module pin#7 (gen-wht wire) voltage is 13.58.
Please let me know if additional testing is needed.
Also in addition to the lights I listed as working above I noticed the trunk light is also working.
Thanks, Joe
 

billr

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I am convinced the module is bad. You could confirm by trying what Dan suggested: disconnect the module from the harness, then jumper the harness pin 1 to pin 7 and see if the brake switch now actuates the brake lights.

For just doing this test to confirm the module is bad, you do not need to cut and splice the wires, just use a jumper at the harness connector.
 

josiah

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Mobile Dan, Billr, Grcauto and Jackc,
I did as instructed above (jumped sensor pin#1 to #7). Pressed brake pedal. All 3 brake lights now light. Glad to see that.
Any additional questions or advice would be appreciated.
Thanks, Joe
 

billr

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What is going to be your permanent fix? Are you going to leave the module connected, so that the tail/side lights work; and leave that 1-7 jumper in place so the brake part of the module is bypassed?
 

Mobile Dan

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I'm going to suggest that you cut/join the wires as suggested in reply #64. Don't cut the wires too close to the connector (in case you want to reattach the wires at a later time).
 

josiah

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Mobile Dan and Billr,
Right now I am considering the following:
1) Replace sensor. I plan to check and see what a replacement sensor ( new or used) would cost. As mentioned previously I already checked Rockauto; but did not find it listed. Jackc in a previous reply said they are expensive. However considering how old the car is this may not be a practical option.

2) billr, I had the same thought you had above; that is, leave it jumped.

3) Mobile Dan, I really don't want to cut wires. I'm sure your advice is good; however I'm afraid I may fail in executing your advice(translation-> afraid I might screw something up).

Thanks for your wise advice.
I plan to let you know what I decide to do.
Thanks, Joe

grcauto,
By the way, the wiring diagram you provided in reply#9 was very helpful. Please provide source. I have a 1987 Toyota service manual which has a wiring chart but it is not as detailed as the one you provided.
Thanks.
 

JackC

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I understand your fear to cut wires, but since these modules are problematic and not even installed on most cars at all, if it was me I would wire directly and eliminate that potential problem forever.

On the other hand, replacing the module is easy but costly but may have to be done again sometime down the road.

Of course it is your call. Either solution will work. But I would not purchase a used one as it may have the same problem or will soon after installation.
And remember that new today does not mean it is OK, it only means they will probably give you another one under warrenty if the first one or second one fails. Called customer quality control.
 

grcauto

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Do yourself a favor and by pass that crap module. The diagrams I have are from an old MOD program good through 1999. I can get you what ever you need if you tell me what system you want.
 
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