1990 Camry Lamp Out Sensor Questions

[BugDiddy]

Hey guys my lamp out idiot light has been on for awhile and I was trying to troubleshoot it. I pulled out the little yellow box and it does not look fried, although I know sometimes electronics can look ok but be bad.

All lights are good and I haven't replaced any of the bulbs which leads me to believe its the little yellow box.

I searched and saw most people just replace that box which I don't have a problem with. However I was wondering how I could override that little box. I'm sure its just a matter of crossing the right wires but I'm not exactly sure which ones.

That light has been bugging me for awhile now and I just want it out. I don't mind not knowing if there is a light out.

[atobe]

instead of figuring out how to reverse engineer that box why don't you just take out the cluster and remove that light from the back.

[TBayToyotaBoy]

^^I second that motion...that's what I did with my ABS idiot light

[BugDiddy]

I would do that, but I'd rather not tear apart the dash. I just thought that wiring it up in the trunk would be easier.

Plus I'm not actually 100% sure its the box. It doesn't look fried.. I'm guessing I could test it with my voltmeter but I'm not sure how.

[toyomoho]

Cut the Yellow/Green wire at the sensor to turn off the light. Tape off both wire ends to prevent shorts.

To bypass the sensor connect Green and Light Green wires, connect Green/White and Green/Red wires disconnect and tape off Yellow plus the wire listed above. The White/Black wire is ground.

But first check all bulbs, sockets, wiring, etc. The bulbs can still work OK but the sensor be on due to corrosion, a failing bulb, etc.

[new echo owner]

Have you check to make sure you have the correct bulbs installed? And they are all working properly?

N.E.O.

[BugDiddy]

I never thought to check the bulbs to see if they are correct... I haven't replaced any of them and the light wasn't on before, so that leads me to believe that the light is on due to corrosion or a bad sensor.

I am going to go test for corrosion right now and if there is anything wrong with that.

Thanks again for the help

[new echo owner]

I guess I should follow closer to what you had wrote in the OP.

If you can determine when the warning come on, maybe you can narrow down to what circuit to check; if it comes on only when you have the parking lights on or when you step on the brake pedal. And then there are times, if you have a bad ground, it will only come on when you have the parking lights on and step on the brake pedal.

N.E.O.

[BugDiddy]

Ok I just went out and did some basic DMM testing. I only get ~.6v to the power (yellow/green wire). I also tested from power to ground and I got 25 ohms.

I'm not sure if the ohms matter, but I'm betting I'm supposed to have more than .6v to the power of that sensor.

Oh yeah, the idiot light only comes on when I press the brake pedal, if that helps narrow it down.

I'm probably overthinking this whole sensor, but I like knowing why something goes wrong rather than just clipping the wire.

[new echo owner]

Check all the brake light bulbs and their gorund. The yellow/green wire comes from or goes to the warning light in the cluster, so with the light on the voltage drop would end up being only 6v. If any of the brake light bulbs show any blackush soot inside, there is a good chance that it is on it way out. Also compare the brightness of the light, it might just show you which one mya be the cause of the warning light.

N.E.O.

[BugDiddy]

Well I found a bulb that was very slightly blackened so I put in a new one without any luck. So I snipped the Y/G and voila no more idiot light.

[new echo owner]

You have disable the warning light., is that what you want to do?

N.E.O.