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 Jeremy Your Own Question
Jeremy
Jeremy, Certified Truck/Bus Technician
Category: Medium and Heavy Trucks
Satisfied Customers: 2783
Experience:  ASE Med/HD Truck Technician, NATEF Diesel Engines and Electrical/Electronics Technician, EPA 608/609 HVAC Certified, Steering/Suspension and ABS/Brakes Technician
9290743
Type Your Medium and Heavy Trucks Question Here...
Jeremy is online now
A new question is answered every 9 seconds

I have a 1999 Kenworth t600. When I turn my low beam

Customer Question

I have a 1999 Kenworth t600. When I turn my low beam headlights on , my low beam bbulbs are bright and my high beams come on dim. When I turn high beams on high beams come on and low beams get dim. Any ideas thanks brad
Submitted: 10 months ago.
Category: Medium and Heavy Trucks
Expert:  Jeremy replied 10 months ago.

My name is ***** ***** I will assist you.

You are describing a faulty multifunction switch. The switch is bad inside the turn signal stalk where the high beam switch is located.

Give it a swap and the issue should resolve.

How it should be is low beams stay the same and when you click the switch, high beams come on as well. Your switch is broken internally and crossing the light wires instead of changing them.

__________________________________________________________________________________________________________________________
You want a 5 star service and I want to provide a 5 star service. Please consider that I don't know your skill level as well as I can't see,
touch, smell, hear the vehicle/machine in question. Please provide as much detail as possible and I will provide as much back.

Once an answer is provided, you should see a rating screen. Please rate my personal service to you. The ratings are my personal feedback,
they are not the site feedback.

Thank you for allowing me to assist you through Just Answer!

Jeremy

Customer: replied 10 months ago.
Already replaced it, still doesn't work. Also replaced wire harnesses from headlights to the plug behind the bumper
Expert:  Jeremy replied 10 months ago.

Well, the one thing I would have expected it for sure isn't it.

Hmmm...

There is a dimmer relay on the truck. That would be the only other thing that could cause that besides grounding/power issues in the harness in the cab.

If you add a ground to the circuit, there is no difference?

Click HERE for the diagram.

Customer: replied 10 months ago.
Replaced the relay, also tried running another ground
Expert:  Jeremy replied 10 months ago.

Thee can only remain an issue in the harness in the cab then. Something is crossed and working right or the wrong lamps are used. There isn't anything else I can think of. I'm stuck without actually putting my hands on it...

Customer: replied 10 months ago.
I tied clicking on your diagram but it did not work
Expert:  Jeremy replied 10 months ago.

I just checked it and it is working good. I had another check it and he had no issues either.