Yes, you do not need to remove the steering wheel to remove the multifunction switch. Use a 1/4 inch ignition wrench to hold a T25 bit to remove the lower screw holding the switch.

 

I've got a weird problem - my DRLs work fine but when it gets dark out the low beams don't turn on and I here a clicking in the dash. The parking/fog/dash lights turn on and work fine. I can correct the issue by just manually turning on the headlamps. Is this a bad sensor on the dash? Everything else works on the car so I don't think it is a BCM or mutifunction switch issue.

 

Its not a bad job to change.. I lost my torq driver in the wheel when i pulled it back... Crazy sheit.. Drilled a hole in back of wheel down low and got it out with a magnet

 

I replaced my multi function switch still no low beams and my power windows do not work. All fuses and ground on the shroud are good. DRL's work but when I cover the sensor (during the day) the low beams don't work.

 

Sorry don't know the age of your MC so it will be kind of hard to give you very good advice. If it was in 2000 to 2005 years, The headlight Relay for both High and Low beams are same Relay. Does either of your high and low work? If you take your multiswitch and pull does the highs beams come on. It don't matter if your DRL are on or not the BCM will turn the DRL off and toggle on the Highs... If they don't then it could be there is an issue with your normal Head light Relay...

It goes from your BCM on ground to the Head light relay. From there it sends a ground over the Multi Switch out to a Splice, Then to the head light ground. 12v is always there on the power side of the headlight.

Here is a Problem. Your DRL work. So that tells me that your wiring is in tact. The drl turns your normal Highbeams from Parallel setup to a 1/2 power Series setup. I guess I have to ask!? Did you turn on your head lights? or where you just trying to get the Auto Lights to come on?

So then it is also hard to say for sure what your problem is with 2 issues that don't share a Splice or Ground. SO you said that your grounds and wiring was in good shape it almost sounds like you have a Bad BCM. Without being there and having a scanner on your OBD II Port. It is hard to say that it is bad so From what you wrote that is what it sounds like to me..

Hope you find out what the problem is
James

 

Thanks James! I have a 03 Monte. I swapped the relays and the pull switch for the headlights. When I pull the headlight switch nothing happens. I thought I had it figured out last week, when I chased the grounds and swapped relays. The low beams worked all week until yesterday. I have had issues with this car and its BCM, I have replaced it three times since I bought the car new in 03. I finally pulled the Viper alarm that Chevy says was killing the BCM... I know the BCM is locked out right know and has been locked out for a year or so. Since it has not been giving me any issues I have left it alone. I put LED's in the low beams and they worked fine until last week. I put the old stock bulbs back in, thinking it was a power draw issue, no joy. Thanks for you input!

 

Does the BCM control the power windows? I think if I can find out how the power windows and low beams interact that would be the solution. I am going to swap the window switch and start shooting wires from there.

 

BEFORE you do anything else from my testing I would say try this that may or may not help. Unplug the Battery from the car. (Go to the BCM and unplug the 3 connectors and plug them back in. Do this 3 to 5 times.) I know it is a PITA however it could be that they are not making a good connection in the holders and by doing this makes a better connection.

I am not 100% sure about this. However if I remember right only thing that would be connected for the Windows to the BCM is the RAP control power side of RAP relay. So the other side of that control is ground. Once the Control power from the BCM is sent the Relay latches and power is passed from another fuse in the box that is a main 60amp.

It could be BCM related issue or RAP Relay issue. RAP Relay and Headlight relay is in the Left side Fuse box and could be Related to your Left side Fuse box as well. There is loads of tests that needs to be done to rule all things out to the end issue. One of the problems having a dealer or shop do this testing is that it all takes time. For the Dealer there are things they can do with the Tech 2 Scanner that can speed up testing.

For your Headlights.
IF you are able to do some testing you can if you have a test light make sure you are on a good ground. Test the Yellow wire that is coming from the Headlight switch. Or you could if you felt like it take a wire and introduce ground to the Yellow wire. This wire goes to the BCM and is a ground. IF that ground gives your Light Relay the info to turn on your headlights there is a problem with your Headlight switch. If you have access to the back of the light switch it could be as easy as just adding a jumper wire on the D pin of your light switch harness to a good ground. That would be the same as turning on your headlight switch to the headlight position.

Main issue with the MC and Impala alike for 00-04 is that it is setup on a very complex computer system in the BCM. When the DRL is active it is your Highbeams at 1/2 power because they are running in Series. When you command them on or the Auto turns them on. The DRL turns off and Headlight Relay turns on the Normal light path that run in Parallel. Most times when there are LEDs in place they can back feed the BCM and in turn can trash the BCM. That is why if I was to use LED's I would change the wiring output from ground to a 12v over my own Relays and Diode isolate my wiring from the bcm wiring.

In the End, There are only a few things that can go wrong. These are in no order..

BCM, Multi Switch, Headlight Relay, Head light fuses, Or Light Switch.

Under the hood Box there is 2 fuses. One that works the Right one that works the left. We can rule them out because you said that your DRL is working. Not only does that tell me that your fuses are ok. Because without the right fuse, you wouldn't have any light at all for DRL. Without the Left one your DRL relay wouldn't turn on to make your DRL lights work. Then the Next thing to test is Does your Multi Switch tell your Highs to come on? To do this test, Make your car so it can't roll if your parked on a hill, Turn the car on (Don't start it) Shift into gear, The DRL should turn on, Take your left hand and slightly pull back on the Multi Switch Lever, This will turn off your 1/2 power DRL and turn on your HIGH BEAMS (Light on dash for Highbeam would turn on too) When you let go the DRL would come back on. After testing put car back in park and turn off car. If that didn't turn on the Full power High beams it could still be an issue with BCM, Multi switch. When you pull to flash your High beams that path goes to a ground that bypasses your headlight relay.. However that still don't mean the Relay isn't at fault as well. IF it don't work you need to check the grounds in the Kick panel area. That ground is shared with a splice that goes to the headlight relay as well. Could be a bad ground.

James

 

James, thanks for your time and ideas. I will give them a try the next time my low beams go out. I was shooting grounds inside the headlight assys (they all checked out) and the lights are now working. WAPINTA! I am sure it is a ground/BCM issue. I think introducing a ground to the yellow wire behind the light switch and controlling that new ground with a toggle switch will "fix" the low beams and windows without tearing everything apart and help if they go out while driving down the road.
I have 50W 6 Ohm LED Lights Load Resistors. I think that will fool the BCM into thinking the LEDs are standard bulbs. Thoughts?
Thanks Again, Brian

 

Just got the issue fixed at the dealership. They found a damaged (warpped) ground terminals the left side instrument panel fuse block. I have no idea where that is hiding or how I missed it. If anyone has a picture or actual location of that terminal is, I would love to see if. I believe the schematic say it is a ground distro. Really just want to update everyone. Thanks for the help as well!