Chevrolet Repair Questions? Ask a Chevy Mechanic for Answers ASAP
Hi my name is ***** ***** I will be happy to assist with this today.In some cases I may need more info to assist better.I apologize for any delay.
This can be due to an internal electrical fault with the BCM ( body control module).This control unit controls the light ground signals to power them on as well as the signal for the instrument cluster for high beam.The head light switch feeds its signals into the BCM and then the BCM feeds signals out to the dimmer switch to control the light signals.In some cases it is the multi function switch that causes this if it has an internal short.It can still work to operate the turn signals but can fail to allow the signals to pass through to allow head light operation.
To determine which is at fault here the signals have to be tested with a multi meter to see for sure which is the cause needing replaced.If you have this tool to do this testing and want to test it let me know.
If more help is needed, use the reply tab to continue our conversation. If no further assistance is needed, kindly rate my service,your 5 star rating is appreciated ( should be a link to click on here or above).You can rate at any time and we can continue to work on your question as this will not close out your question.Keep in mind in some cases it can be difficult to fully diagnose or help repair your vehicle without seeing it and I work on delivering the best possible answer from what I see to work with.