KC98LS

Hello there, apologies if this has been asked before, I searched around and didn't find anything.


I recently bought a 1998 LS400, when I open the rear doors, the lights on the left side don't turn on, however pressing the button turns the right, and left map light on. The center light never turns on though.

I popped the cover off, and tested the bulb in the other socket, and it worked fine. I also popped the light assembly out, and tested the voltage using my multi-meter. The right side, which works measures 12V, the left side which doesn't measures 2.85V.



Any input on what might be the problem here?

Of interest, all of the other lights appear to work in the car, also all of the interior lights are LEDs, being a 1998 I assume this is stock, but correct me if I'm wrong.


Pic related, the part that's hanging down is putting out 2.85 volts, whereas the right side is putting out the correct 12v.

sha4000

iTrader: (1)

No those LEDs are not stock. The previous owner put them in there so maybe they messed something up.

KC98LS

Good to know, any ideas what they may have messed up?

I heard there's an integration box that controls interior lighting, would that somehow partially fail?

Yamae

There are semiconductors in that box and those fail when a short circuit is caused because of too much current but less current to open the fuse. You probably need to replace the box to fix the problem. I knew a young guy who failed trying to install a led light bulb and accidentally he made a short circuit. He ended up to replace the box at the dealership.

Dealerships only replace the unit and owners need to pay some big money. But this is very common among modern cars. I often fix those different units as a volunteer and I know how easy to fix those units just finding the failed component and replace it. This needs some skills, but people need to know electronics affairs some more.

KC98LS

Good to know, what exactly do you mean by the box?

timmy0tool

iTrader: (7)

sounds like you simply have a burnt out LED. most LEDs are made of poor quality and don't last as long as they claim to. change to a regular bulb and see if you still have the problem.

next i would check your door pin triggers. they ground when the door is opened to trigger the light to turn on. they are located in the door jams and is usually covered in rubber. if the rubber is torn, there is a good chance gunk has built up inside and is intermittent.

KC98LS

I actually tested the bulb, and it is good.

I'll try the door pin, any tips on how to do that?

Thanks.

Yamae

You need to replace the integration box which controls interior lightings. The output voltage 2.85V from the box simply means that the box is not working properly. The semiconductor inside must be damaged. Toyota does not supply those semiconductors as parts and usually there is almost no way to fix the box. Only those who analyze the circuit and replace damaged parts can do some. I seldom find those people though.

KC98LS

Where exactly is the integration box located in the car?


Also, update: The left rear door switch or whatever you want to call it definitely works, as opening the left rear door, turns on the bottom door light, and the dash door open message.

Yamae

A JDM has it under the dash near the fuse box. I don't know about the USM.
Don't pay any attention for the switch. Simply tackle the box. The most inexpensive way may be to go to a junk yard and buy the box and replace it.

KC98LS

Does anyone have any ideas on where the integration box is in the US model? Been a bit busy, and haven't looked for it.

Update: Is this what I'm looking for?

KC98LS

Bump!

Any input would be greatly appreciated. I really want to fix this issue, and get it off of my list.

Update: any other input?