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Discussion Starter · #1 ·
So yeah... Bizarre problem has cropped up in the last week or so. My driver side DRL Eyebrow shuts off when I hit the brakes and then turns back on when I release the brakes. I haven't changed a thing with bulbs or electrical in quite some time. I tried unplugging the connectors (light assembly and DRL) and shooting air at them, but that hasn't worked. Going to try the ole battery reset in a bit, but anyone have any ideas otherwise?
 

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How old is your battery?
 

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Discussion Starter · #3 ·

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Well I'd say that would be an excellent place to start. When voltage gets low or the battery gets weak on these cars strange things can be afoot at the circle K...
 

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You're not running aftermarket LED turns or brake bulbs are you?
 

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Discussion Starter · #6 ·
You're not running aftermarket LED turns or brake bulbs are you?
Yeah understood on battery life. I was suspect of that.
I am running all LED’s but have resistors for the turns. Have had those in for years though without issue. Also no issue with those lights flickering
 

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It's always a valid concern for me. Remember that the BCM controls everything lighting related. I've see things were resistor (especially the gold 6 ohms) being to fail and get extra hot. This in turn damaged brake lamp wiring and caused a big mess of things.
 

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Discussion Starter · #8 ·
It's always a valid concern for me. Remember that the BCM controls everything lighting related. I've see things were resistor (especially the gold 6 ohms) being to fail and get extra hot. This in turn damaged brake lamp wiring and caused a big mess of things.
Not the most skilled in electrical although I installed this stuff, but how would I check on that? Resistor would not have continuity if fried but that’s about it
 

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Melted plastic is pretty easy to find LOL.

I'd just check the battery out first. It's due.
 
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Discussion Starter · #10 ·
Melted plastic is pretty easy to find LOL.

I'd just check the battery out first. It's due.
Lol the resistors look good.
The battery had corrosion on the negative terminal but is sitting at 12.6 on its own. I’ll clean it up, slap it back in there and check how much the voltage drops
 

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I had this EXACT same problem start about 5 months ago. Similar situation - RS tail light swap with LED blinkers front and rear, LED reverse lights. Had resistors in them for over a year with no issues. Then all of a sudden, the DRL turns off when applying the brake. I also have constant hyper flash on the same side.

I tried all the basic things - checked all connections, tested resistors, wiring, and battery, etc. After swapping bulbs and my own complete light housings, I determined the issue is coming from somewhere in the driver rear tail light area. I replaced my turn signals to halogen bulbs in the rear and the DRL issue when braking, stopped. However, I still have constant hyper flash on the same side. I tried swapping entire tail light housings with someone who hasn't modified any bulbs and I still get hyper flash.

I've concluded I have a wiring issue somewhere in the driver rear - my resistors did get super hot and I think they may have damaged something. Frankly, I've gotten used to the hyper flash so it's not worth potentially spending hundreds of dollars to me.

Overall, I don't have a solution other than to try going to halogen bulbs to see if that does anything. Other than that, my story is one of sympathy lol
 

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Discussion Starter · #12 ·
Overall, I don't have a solution other than to try going to halogen bulbs to see if that does anything. Other than that, my story is one of sympathy lol
Well damn lol in a way I'm glad I'm not the only one, but that also sucks you never really got the root cause. I'm gonna see how the battery being cleaned off and disconnected does for a few days and then swap bulbs to see if that changes anything. Might also consider changing the resistors although they appear perfectly fine. What a frustrating issue

I also had an issue a few years ago with the other DRL. It was changing brightness randomly; like dim as hell to WAY too bright. Ford had an engineer come from Michigan to look at it and fix it, but no one took any notes on what he did and he was gone when I got there... So this is now DRL issue #2 for me
 
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Discussion Starter · #14 ·
I also was having the key not recognized lately, so that thread will be useful. I cleaned corrosion off of the negative terminal and connector (connector had the most) and changed the key fob battery. Next steps will probably be a new battery and connector after seeing what this cleanup step does (if anything). Battery was sitting at 12.25 sitting for a day, but then 12.4 after running for a few minutes. Drop at startup was around 10.5
 

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I also was having the key not recognized lately, so that thread will be useful. I cleaned corrosion off of the negative terminal and connector (connector had the most) and changed the key fob battery. Next steps will probably be a new battery and connector after seeing what this cleanup step does (if anything). Battery was sitting at 12.25 sitting for a day, but then 12.4 after running for a few minutes. Drop at startup was around 10.5
4.5 years for the battery is really pushing it. I'd opt to replace and then do a BMS reset.
 

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Discussion Starter · #16 ·
4.5 years for the battery is really pushing it. I'd opt to replace and then do a BMS reset.
Yeah I was already getting towards a new battery, so this might be it. Didn't even know about the BMS reset before yesterday and looking into this stuff lol would've never thought about it so thanks for the callout!
 

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Discussion Starter · #17 ·
New battery and no dice. Still doing it. Reset the BMS as well
 
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Discussion Starter · #18 ·
When I swapped the brake lights back to OEM bulbs from LED’s, now the Eyebrow is off in Lights Off mode. It comes on at 50% at running light mode and lights on mode. Other eyebrow is 100%, then 100%, and 50% working through the same 3 modes
 

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Discussion Starter · #19 ·
It’s all whacked out now... put the LED’s back in after trying OEM bulbs in turns and brakes. Now neither eyebrow is on, hyper flashing driver side turn signal. WTF is going on?!?
 
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