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2017 Ford Focus ST3
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Discussion Starter · #1 ·
I’ve got an interesting issue that I’m at a dead end on trying to solve, my passenger side headlight refuses to work. I’ve replaced bulbs ballasts and even swapped it to another car and everything works (signals, DRLs etc) but the actual forward light. It’s an ST3, Any suggestions on fixing this?
 

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2014 ST3. Garrett Powermax turbo, Thermal Turboback, CPE intercooler, JBR intake, Innovative RMM
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So, for clarification, the forward light (the D3s bulb) did NOT work when plugged into the other car?

Id inspect the harness that goes from bulb to ballast as well as the internal wiring inside the housing that goes from the bulkhead connector to the ballast.
 

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Discussion Starter · #3 ·
So, for clarification, the forward light (the D3s bulb) did NOT work when plugged into the other car?

Id inspect the harness that goes from bulb to ballast as well as the internal wiring inside the housing that goes from the bulkhead connector to the ballast.

Correct, sometimes it will flicker on for a second or so then go back out.
 

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Discussion Starter · #4 ·
So, for clarification, the forward light (the D3s bulb) did NOT work when plugged into the other car?

Id inspect the harness that goes from bulb to ballast as well as the internal wiring inside the housing that goes from the bulkhead connector to the ballast.
also I forgot to mention that there’s no light on the dash that indicates there’s a problem. Basically the car doesn’t think there’s anything wrong.
 

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also I forgot to mention that there’s no light on the dash that indicates there’s a problem. Basically the car doesn’t think there’s anything wrong.
So i would think the issue might lie between the ballast and bulb. You can buy those cables used for cheap.

Could be wrong but the BCM cant monitor post- ballast.
 

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A girl in a local forum is having the same issue. She found that one of the wires from the ballast to the bulb was intermittent.
 

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Discussion Starter · #7 ·
A girl in a local forum is having the same issue. She found that one of the wires from the ballast to the bulb was intermittent.
thank you! I’m going to look tomorrow afternoon, I’ll try and report back
 
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