Dash lights not working radio stays dim at night.

[Brandon]

Hello,

I have a 2003 Buick century, that has a problem with its interior lights, on the cluster panel, and radio.

The car has a automatic feature that is supposed to turn on the Dash lights and the headlights at night.

The headlights come on fine, however my speedometer, and everything else stays dark, the problem used to be intermittent, now they never work.

I have searched and found some info about replacing 4 resistors on the cluster panel, which I did. apparently that was only for the PRNDL, as it did not help my speedometer lights. I have also replaced the light switch, which fixed the issue but only for a short time, then it started again.

I have visually inspected all the fuses I believe could be related, they all look to be in good shape. I imagine that it has something to do with the sensor, that is supposed to make the lights automatically come on, but I am clueless on this issue.

All help is appreciated, thanks!

Topic

[dave]

Ask and ye’ shall recieve. Your problem is as follows:

This is what ye’ got:

And these are the specific circuits that affect the aforementioned inoperative devices:

The stuff marked in blue are your instrument panel lights.

Test points are numbered 1 through 5 in descending order of priority.

[b][i]**Anything in the orange highlighted circuit will knock out both your radio and your instrument panel lights.

[/i][/b]There appears to be in inline fuse inside the headlamp switch that I am confident is a common point of failure (test point #1). Therefore, the easiest place to start and the most likely cause of the problem will be the headlamp switch. Pull the switch, turn it to “Head” and test for continuity between pins “O” and “I” (pins associated with ‘orange’ and ‘grey/black’ wires). If open, replace headlamp switch.

Hopefully at this point your problem is solved. 🙂

If not, then…
(more comprehensive testing follows)

There is a pretty hefty splice point at S212 (Test point #2). You should locate this splice pack and probe into the wires and test for voltage. 200 level connections are located inside the vehicle under the dash. Use schematic color coding to back track from easy to get to devices and locate the splice point and test for voltage. Make sure the headlamp switch is in “Head.” If no voltage, perform wire repair.

Test points 3 & 4 can be easily tested if all the stuff in the green highlighted box works. If some or none of these devices work, then you will need to pull the headlamp switch and test for voltage at pin “H” (gray wire). If voltage, then locate splice pack S203. Back trace color coded wires from easy to get to devices until you locate the splice pack. 200 level electrical connections are located inside the vehicle under the dash. Probe into the wires and test for voltage. If no voltage, perform wire repair. For all measurements, make sure the headlamp switch is in “Head.”

If all the stuff in the green box works, then go straight to test point #5. Pull the instrument panel and test for voltage at pin “J” (gray wire in connector C1). Again, make sure headlamp switch is in “Head” to energize the circuit. If no voltage, repair open circuit. If ‘low voltage’, locate damaged wire or connection and repair.

I don’t usually like to speculate and take guesses, but I am 99% sure you could just go to autozone and throw this $5 part at your problem and save yourself a lot of testing:

Dorman/Conduct-Tite 15 Amps 180 Watts fused 3 position push-pull switch
Part #85989

Although not mentioned, I am willing to bet that your HVAC temperature control head lights are also inoperative. B)

Attachments:

• buickcent.png
• dimswitch.jpg
• buickcent1.7.png

[college man]

Looks like some troubleshooting is going on. 😉

[Brandon]

Thanks! that some really detailed info. (slightly over my head too! lol)

When you say to put the headlamp switch into “Head” what are you referring too? Just turning the headlight switch to the on position?

Also you are correct on the Hvac light, it flickers/does not work. and the defrost button.

I forgot to ask about a switch to just bypass my issue. If i were to go the route of the switch, where would i splice that into?

Thanks! 🙂

[drthrift035]

Great explanation Wrench Turner. I like how you put out the diagram. Electrical is such a weak area for me. You are really on a higher level. Any suggestions for me to improve on my electrical skills. Again, hats off to you ! Keep it up.

[dave]

When you say to put the headlamp switch into “Head” what are you referring too? Just turning the headlight switch to the on position?

Yes, just turn the headlight switch to the “ON” position.

I forgot to ask about a switch to just bypass my issue. If i were to go the route of the switch, where would i splice that into?

You’d think a simple 3 position toggle switch would work; however, the headlamp switch has internal logic that controls a lot of stuff. You’d be better off just replacing the switch.

[Brandon]

Thanks again!

First i will test my head light switch (and cross my fingers that’s the problem.) You mentioned a inline fuse, in the switch, would it be replaceable? or would I be looking at a whole new switch?

Is it possible to Wire the mentioned interior lights to be on 100% of the time when the car is on? (It sounds like its not a good idea, but I thought I would ask.)

[dave]

Any suggestions for me to improve on my electrical skills

.
Believe me, I would have never have been able to come up with this stuff before I my auto electric classes at school. After taking electrical fundamentals (which I learned a ton) and advanced automotive electrical systems, I think I can pretty much do anything with auto electric.

But in the meantime, you could look through some books to get a good grasp of the related subject matter:

http://scannerdanner.com/

There are also a lot of youtubes on automotive electric:

And lastly, you could just look at the ASE practice test 🙂

http://www.freeasestudyguides.com/a6-electrical-test.html

[dave]

You mentioned a inline fuse, in the switch, would it be replaceable? or would I be looking at a whole new switch?

You will need to replace the entire switch. You’ll notice in the wiring diagram that the inline fuse(test point #1) is actually inside of the dotted line which represents the component itself. Luckily, much like my women, this is a repair that is cheap and easy.

Is it possible to Wire the mentioned interior lights to be on 100% of the time when the car is on? (It sounds like its not a good idea, but I thought I would ask.)

Yes, of course this is very possible. It would probably involve splicing your interior lights into a circuit that is hot in ACC and RUN.

[Charles]

I have the same problem , So do you have a pin diagram on both pins because my wire colors are different? Can you show pin configuration?

[Charles]

#5. Pull the instrument panel and test for voltage at pin “J” (gray wire in connector C1). Again, make sure headlamp switch is in “Head” to energize the circuit. If no voltage, repair open circuit. If ‘low voltage’, locate damaged wire or connection and repair. need pin layouts for plugs?

[Caleb Stovall]

You should be able to take manual control of your lights with the switch and manually turn them on without input from the sensor. Try that out and see if your lights come on that way, that’ll rule out the light sensor.0

[Author]

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