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2015 Ford Fiesta - Low beams intermittent

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Lavon
State
TX
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What I Drive
2015 Ford Fiesta
#1
My wife's 2015 Fiesta has a light issue. whenever you start the car, both low beams work will work for a few minutes before both low beams start to turn off at random times. Right when the issue is about to start, a small repetitive click can be heard coming from the engine bay. It goes away, then both lights remain on. light clicking begins, both low beams will randomly shut turn off then reappear once again. What's the issue?
 

Handy Andy

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Grand Rapids
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#2
Hmm...The lights themselves - are always supplied power thru the main power relay when the engine is started. The lights go out when the engine is shut off or the light switch control knob is turned to OFF - you have the final say, but when you turn off the ignition - unless AUTO (A) is set on the control - the lights also go out.

If you encounter a flickering then they stay on, does this occur as you drive? I'm trying to help in thinking if vibration of driving is causing this - then the under the hood Engine Fuse block might need to be investigated. There are also grounding points for the harness and the lamps - but the LAMP switch HAS the Ground wire or main return - so if the lights flicker - two places to check - press down all the relays and fuses in the engine compartments fuse block and also locate the light switch inside and see if it's knob is loose. As you operate the switch (do this when the engine is running so you can try to recreate this) try tapping or flexing/Torqueing on the knob thru the turning range and see if the condition can be repeated or even occur.

It is my thoughts that either the wiring harness in the engine compartment needs some service or the light switch is nearing the end of it's service life or it somehow got kicked or "took a knee" when someone got in the car - loosening the knob from the index shaft and now it makes an intermittent connection until the tiny spark of current can spot weld the contact on until it's shaken loose by rotating the knob back to off.

Setting it to Auto won't help because if the shaft is damaged, the switch will just be as intermittent on Auto as if it were on any other setting except off.

So you can always force the Auto function on by jumpering the wiring harness and deal with the car wanting to run lights in Auto all the time - but if you're doing this to save the electrical and battery - you'll need to verify it's not the switch or the fusebox causing this.
 

scotman

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#3
Sounds like a relay is failing. Or possibly some wire in that circuit is exposed and shorting!
Has the car ever been in a front collision?
 
OP
K
Messages
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City
Lavon
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2015 Ford Fiesta
Thread Starter #4
Hmm...The lights themselves - are always supplied power thru the main power relay when the engine is started. The lights go out when the engine is shut off or the light switch control knob is turned to OFF - you have the final say, but when you turn off the ignition - unless AUTO (A) is set on the control - the lights also go out.

If you encounter a flickering then they stay on, does this occur as you drive? I'm trying to help in thinking if vibration of driving is causing this - then the under the hood Engine Fuse block might need to be investigated. There are also grounding points for the harness and the lamps - but the LAMP switch HAS the Ground wire or main return - so if the lights flicker - two places to check - press down all the relays and fuses in the engine compartments fuse block and also locate the light switch inside and see if it's knob is loose. As you operate the switch (do this when the engine is running so you can try to recreate this) try tapping or flexing/Torqueing on the knob thru the turning range and see if the condition can be repeated or even occur.

It is my thoughts that either the wiring harness in the engine compartment needs some service or the light switch is nearing the end of it's service life or it somehow got kicked or "took a knee" when someone got in the car - loosening the knob from the index shaft and now it makes an intermittent connection until the tiny spark of current can spot weld the contact on until it's shaken loose by rotating the knob back to off.

Setting it to Auto won't help because if the shaft is damaged, the switch will just be as intermittent on Auto as if it were on any other setting except off.

So you can always force the Auto function on by jumpering the wiring harness and deal with the car wanting to run lights in Auto all the time - but if you're doing this to save the electrical and battery - you'll need to verify it's not the switch or the fusebox causing this.
So I actually ordered a new light switch for the interior and it didn't do a thing. The high beam is permanently out on the passenger side and has been out for some time (bought a new headlight and that didn't fix it either, so I sent it back). The low beam on the passenger side was the first to go out but the driver's side would actually still run like normal including the high beam. Now both low beams will go out intermittently. They stay on for a few minutes, then turn off (even with the lamp switch ON, not on AUTO), flicker, then remain on once more for a few minutes and it does the cycle again. However, the high beam on the driver's side functions normally. I've checked the relays in the engine compartment and they all seemed fine.

I can't tell whether it's a fuel injector, but when the engine runs, there's an additional and very quick successive ticking coming from, it sounds like, between the engine and the battery. It's on the right side if you're facing towards the car at the front. But when I turn the engine off, and leave the light switch on, no noise, but the lights still will do their on and off dance. Oh, and this problem happens not matter if I'm driving or sitting in the driveway or parking lot. Can't drive it at night but it runs no problem. No engine vibration or weird noise coming from the engine itself. We had a timing belt and crankshaft wheel replaced a few months back.
 
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OP
K
Messages
3
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0
City
Lavon
State
TX
Country
United States
What I Drive
2015 Ford Fiesta
Thread Starter #5
Sounds like a relay is failing. Or possibly some wire in that circuit is exposed and shorting!
Has the car ever been in a front collision?
It has not. I've pulled the relays and they seem fine. I'm at a loss. I tried replacing the light switch as well. You can check my reply back to Handy Andy for a recap of the full symptoms.
 

scotman

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#6
Trace the headlamp grounds. Given that it is going on eight years old. Kentucky does get some winter type of season. Was the battery replaced in the recent past? If so, was the car driven for some time where it had to be jump started in order to get it started? It's possible that the BCM is failed.
At some point, relays, switch, power distribution box or grounds that circuit is interrupted.
Being 1,200 miles away. I can't take a multi ranging voltmeter and a flashlight and check out the headlamp circuit. So this is just guessing.
 
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