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Jeremy, Certified Truck/Bus Technician
Category: Medium and Heavy Trucks
Satisfied Customers: 3360
Experience:  ASE Med/HD Truck Technician, NATEF Diesel Engines and Electrical/Electronics Technician, EPA 608/609 HVAC Certified, Steering/Suspension and ABS/Brakes Technician
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When the daytime running lights are on it causes the cab

Customer Question

When the daytime running lights are on it causes the cab lights to come and when the signal lights are on my cab lights flash. When headlight on or just park lights everything is fine.
JA: What is the complete model and serial number of your machine?
Customer: Freightliner 2015. GF9961
JA: Are you fixing this yourself? What have you tried so far?
Customer: Yes, I unplugged the wiring harnesses at the lights and I'm getting feedback, it's alright when it's unplugged
JA: Anything else you want the equipment mechanic to know before I connect you?
Customer: I don't think so, how much will this advice cost
JA: I'm not sure of the exact price, but there's only a $5 deposit. The rest of the price information will be on the page I send you to.
Customer: Ok
Submitted: 4 months ago.
Category: Medium and Heavy Trucks
Expert:  Jeremy replied 4 months ago.

My name is ***** ***** I will assist you with your question today.

I'm an independent contractor and I don't get paid until a rating has been made.

We can go back and forth as needed to help resolve the issue you are having. Follow ups are free after ratings, so rate in confidence!

What model is your Freightliner? I ask that because if it is a Cascadia, the lights go through the SAM. If it is a M2, the lights go through the bulkhead. If another model, then it could be different. Each takes a different approach to diagnose.

You mentioned you unplugged the lights. Did any of them stop the issue? If so, stop right there for that light is either bad or the ground to that light is bad. If you unplug all the lights, and the problem remains, then I ask if you have the laptop to connect to test the modules and/or a multimeter to test circuits?

Also, with model info or the full VIN, I can get you a diagram as well.


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!


Customer: replied 4 months ago.
It's a Coronado 3AKJGND17FDGF9961 unplugging didn't stop the problem. I am currently using an iPad but have a laptop here.
Customer: replied 4 months ago.
Is there a fuse for the daytime running lights?
Expert:  Jeremy replied 4 months ago.

The fuse is the same for the headlights. There is a relay for the daytime running lights that is separate.