j9fab

hello all!

i just bought my second LS. this one is a 1994 with 126k miles on it. all factory pretty much everything is really nice and clean. i am having trouble with the interior lighting.

the center console lights do not light up correctly. the gauge cluster works fine, as do all the gauges.

if the head lights are in the off position, the radio backlight, AC backlight and another light work.

if i turn on the headlights to either park or on, those lights go out, and the center console lights are still off

now if i turn the switch on really fast sometimes i can see the console lights flick on for a moment. like one out of 5 times i see them for just a split moment.

any ideas? i am thinking the headlight switch itself, but likely its some module somewhere.

also i noticed, that when i lift on the door handle the dome lights do not come on... maybe related?

other then that the car is really nice, needs a starter since i had to hit it a couple of times to get it to start... but that is it so far!

Yamae

Sound like the body computer is dead.

j9fab

hmmm location and or part #? i have my 93 sitting next to it. if it is easy to swap i will try that!

-jesse

j9fab

so i have been trying to figure this out on my ls.

i have been trying to find where the headlight swtich connector is... anyone have a diagram or location of where it is? looking at the wiring diagrams that i can find there is not a module... only what looks like a junction block. it says location is left of cluster... not very specific.

i have noticed if i have the head lights on, and adjust the brightness the cluster changes like it should. the lights to DO work in the climate control when the lights are on or off stay one brightness until the dimmer is all the way bright. then the climate control lights will get alittle brighter. they only seem to have two brightnesses. the lights i am talking about are the LEDs for what is currently on.

i have also found if i have headlights in the ON position th climate LCD will turn off. the only time the LCD lights are on is when the headlights are in the OFF position. if i turn the headlight switch in between ON and PARK the radio and climate LCD lights will be on at the same time as the headlights.

i have never gotten the backlighting for the buttons to come one and stay on. i see them for a split second when i move the headlight switch very fast.

any one ever taken the headlight switch off?

now that i think about it, could it be the dimmer switch itself? i don't have the diagram here but i do not remember it having dual pots. i think it just a single trim pot...

driving me crazy. my car is so nice and only 126k miles. just these damn lights and the speakers not working.

Amskeptic

This may be difficult to explain. Some of the more complex "logic" circuits that try to answer to a number of different requests will not use dedicated ground paths. That means the some lights can be switched off by having 12 volts applied to both sides of the bulbs.

If the climate control/stereo display illumination is supposed to turn on with the acc/ignition, it has a power path from the ignition.
If the climate control/stereo display illumination is also supposed to turn on with the acc/ignition off/light switch on and you now have it going off, my guess is that you have a possible conflict with the power path.

The backlight illumination is supposed to go on only with the light switch in parking or headlamp positions.

B10 ILL + from PANEL fuse appears to be illumination in to the receiver. B6 ILL - appears to be the ground path to the rheostat dimmer ****

On the climate control head, the ten pin connector is illumination specific. Pins 5, 6, 8, receive voltage from the light switch in park or headlamp positions, pin 7 is the ground path through the rheostat.

Totally not helpful as far as finding a solution for you, but make sure all power paths Dome/Radio1/Radio2 to the climate control/stereo are good.
ColinSometimesIConfuseMyself

j9fab

so if i check the fuses are good, then remove the radio and probe pins 5 6 8 and one doesn;t have 12v when it is supposed to that could lead me down a path to a solution? hell it could be a bad ground also... where it is grounding through a light or coil and like you said then getting 12v on both sides of the lights instead of 12 and ground. i have considered just makeing a jumper from from something that works to the illumination circuit to make the console lights work.

lights that do not work when driving at night:
i think dash button back lights. like the stuff on the left side near my knee [ i assume there are some lights for the buttons]
LCD back lights on radio and climate control
button backlights on radio and climate control [these NEVER come on, only see them work if i move the headlight switch fast. and then only for a split second]
shift lever indicator lights [i assume it has some]
ashtray light [i assume there is light in there]
ALL radio buttons do not light up
some climate control lights work on buttons. like if i enable AC the LED light comes on

i did unplug the radio to see if the lights came one in the climate control. of course this did not work.

i think i will probe 5 6 8 and ground 7 to see what happens

thanks for the reply!

LCD backlights work on the radio and climate control work when the headlights are OFF.
ALL exterior lights work fine. all door lights, courtesy lights, keyhole light, dome lights etc all work they should



i know this is not a common problem, since i have searched all over for a solution

-j