2003 monty SS message states high beam light out, but it is not out, replaced both just in case, no change. using turn signal lights flash rapidly. i replaced the multi function switch, also no change.
one more thing, this issue started after not using my fog lights for many years I tried it, after that the issue started, note if fog lights are on I have no turn signals.

ok, just replaced the fog, headlight & multifunction switch. turn signals still blink fast and still getting message high beam out, I replaced all the bulbs. note: when I put the fog lights on, I have no turn signals. when the fog lights are off, fog light switch flashes when turn signals are used.running out of ideas. HELP
I found a bad ground wire on the fog lights, spliced a wire into it, bolted it to the fender wall, all is well. only took two years !! ground wires are a hard thing to narrow down.

 

You might have two differrent problems.

1. Fast blinking turn signals are usually a symptom of a bad hazard switch. The flasher unit is in it.

2. First scan for codes related to headlamps or foglamps. They start with a "B".
My gut says this is a poor headlamp or foglamp circuit ground problem, but could also be the headlamp or foglamp relay. Try removing one or the other and check for differences, then swap places with them (I believe they're the same).

 

thanks. ya, have changed multifunction, headlight and fog switches, hazard will be next. also because my headlights are always on, want to replace the DRL ambient light sensor but every parts web site I go to nothing is listed or the one they list stated 2005-2007 so not sure what to get. as for the hazard the part number I will order is:ACDelco 10359032. the only part number I can find (but not sure if one for a 2005-2007 will work) is:12450120. one more thing I noticed was when the turn signals are on, the light in the fog light button also flashes. I need to keep this car, so I do not mind fixing it, just wish I could find the damn issue. all this started when I used the fog lights after many years of not using them. this is very frustrating, the dealers are no help, they are guessing, at the rate of pay they get, i'll do it myself.

 

Ya , definitly some kind of a link there, either the Hazard switch or relay.
Rock auto says this is the ACDelco Hazard switch: ACDELCO 10359032 GM OEM $30.79

The ambient light sensor is the same for '99-'07': GM AUTO HEADLIGHT AMBIENT LIGHT SENSOR ON TOP OF DASH NEW OEM 1999-2007 12450120 | eBay

 

Did you ever find problem I have same issue cant figure it out?

 

yes i did. it was a ground wire

 

which one? Wheres it located and what was wrong

 

my issue started when I turned the fog lights on (after many years of not using them) on the ground wire going to the passenger side fog light, I spliced a new wire into it then bolted it to the inner fender. the first place you might want to look will be under the hood on the drivers side you will see 2 wires(I have a 2003 SS, so not sure if yours will be the same) make sure they are intact. also look along the that same frame work to see if there are any other ground wires and check them. I use to live in the north east so a lot of corrosion happened on my car. sad to say, it took me 2 years to find the problem, tried everything under the sun including replacing the turn signal lever inside the car. most likely it is a ground wire, but there are many on the car, start under the hood. good luck. tr this, might not be related but, turn on your fog lights if you have them and see if both are lit and are equally bright.

 

Above the driver side headlight you will see 2 black wires connected to a bolt going into the framing. I took the bolt out and wire brushed the threads on the bolt and cut the ends of the 2 black wires off and twisted them together for now and put it up against the bolt and screwed it back into the frame. Everything is fixed now turn signals working, fog lights working, no more fast blinking all is fixed. I suggest doing this before buying a new switch because it will need to be fixed later on anyways. The bolt is accessible without taking anything off. Pop the hood and it’s right above the driver side headlight you can’t miss it!