How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Pete Your Own Question
Pete
Pete, Auto Service Technician
Category: Chevy
Satisfied Customers: 24656
Experience:  14 years GM dealer Technician.
14928985
Type Your Chevy Question Here...
Pete is online now
A new question is answered every 9 seconds

2005 Chevy C6500 Catapillar C-7 Engine. Last 8 of VIN

Customer Question

2005 Chevy C6500 Catapillar C-7 Engine. Last 8 of VIN 5F700611 Wiring issues with headlights and Low-Beam Lighting? Low-Beam will not work while driving until you put truck into park. When your turn on the dash marker light switch to parking lights, low
beam will come on. When you move switch to regular lighting, low beam switch turns off. Hi-Beam appears to be OK wile driving. Low Beam is the issue at hand. Have replaced dash Light Switch Assembly. As well, Hi-Low beam dimmer switch on the steering column.
Still having the same issues as described above.
Submitted: 11 months ago.
Category: Chevy
Expert:  Pete replied 11 months ago.

My name is ***** ***** I am a professional here at Just Answer. I noticed that your question had not received a response and thought I would see if you still need help with this.I apologize for the delay and I hope I can still assist you with this here.My info is somewhat limited on your model here but I had seen no one else has responded and would like to see if I can help here.If at any time you feel that I cannot help with this please let me know.

Inspect the wiring leading to the head lights and dimmer switch as well as head light switch for any shorted or burned wiring needing repaired.If you didnt inspect the wiring at the head light and dimmer switch this needs done as well.If a connection issue is found at any of the switches like loose or damaged connections this will need repaired.

It is usually a poor connection or poor/damaged wiring that will cause this fault here needing repaired to correct this issue.

If more help is needed, use the reply tab to continue our conversation. If no further assistance is needed, kindly rate my service.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.

Thanks Pete

Customer: replied 11 months ago.
Pete,Was able to Inspect the wiring leading to the head lights and dimmer switch as well as head light switch for any shorted or burned wiring needing repaired. Further inspected the wiring at the head light and dimmer switch.Does not appear to have a wiring connection issue found at any of the switches like loose or damaged connections that needs to be repaired.The issue is simply this. lights do not flicker or go ou why driving or sitting at idle. What is happening is when you put the key in the ignition and turn the lights to the fog light/running light position,position 1 the head light will come on and stay on with
the running lights. They will not flicker or go off. When you try to turn bright swith on in this position, headlights go out. the rest of the clearance lights and running lights stay on. Now when you turn the light switch to the main lighting, position 2 where you would normally operate your headlights and clearance lights being on. Your headlights are out on low beam, you can however switch to hi beam and your lights will come on and stay on. we replaced the switch in the dash, was not the issue. we then replaced the switch on the steering column, the hi-low switch. Again not the issue, no short there. We checked fuses outside the truck and inside the truck to see if a fuse was possibly blown. All seems to look OK on that end. Where should we go from here?
Expert:  Pete replied 11 months ago.

From what you have described this sounds like a possible fault with an ecu internally.I know some models use an ecu to control and monitor the lights and if a fault is within that ecu this can cause this here.Components like a lamp control module/ecu or BCM (body control module) can cause this here.Unfortunately my info isnt showing if and which your model uses here.This will have to be checked into/tested further to pinpoint which component is at fault here for this issue and from there then repaired.

This may require the correct scan tool or computer plugged into your vehicle to check for codes and observe data signals to locate the fault.

Thanks Pete

Related Chevy Questions