Intermittent Headlight Warning When it's Hot Out

4.2 V8 32v Naturally Aspirated - 414 bhp
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dr.electron
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Posts: 17
Joined: Sun Nov 29, 2020 4:09 am

Intermittent Headlight Warning When it's Hot Out

Post by dr.electron » Mon Jun 28, 2021 2:43 am

As the subject states - I get an intermittent warning on the dash about my right headlight when it's above about 80F outside. The error randomly pops up, goes away, and then pops up again while I'm driving. But...if I actually turn on the headlights, the error disappears completely as long as they're on.

Since the headlights aren't on when I'm getting the error, I expect that the car is just checking the ballast regularly. The ballast could be testing the bulb somehow, but given that it isn't a simple resistive element like a halogen bulb, I'm not sure how that would work. Thus I expect that the ballast is either reporting a bad bulb or a problem with itself - either way, the ballast seems the likely culprit.

Anybody else see this specific issue? If I have to take the bumper off to replace a ballast and bulb, then I'm just going to replace both sides. But I want to make sure it isn't something unrelated to the ballast before I buy ballasts...

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Jon_J
5th Gear
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Joined: Sat Feb 04, 2017 12:20 am

Re: Intermittent Headlight Warning When it's Hot Out

Post by Jon_J » Tue Jun 29, 2021 1:57 pm

dr.electron wrote:As the subject states - I get an intermittent warning on the dash about my right headlight when it's above about 80F outside. The error randomly pops up, goes away, and then pops up again while I'm driving. But...if I actually turn on the headlights, the error disappears completely as long as they're on.

Since the headlights aren't on when I'm getting the error, I expect that the car is just checking the ballast regularly. The ballast could be testing the bulb somehow, but given that it isn't a simple resistive element like a halogen bulb, I'm not sure how that would work. Thus I expect that the ballast is either reporting a bad bulb or a problem with itself - either way, the ballast seems the likely culprit.

Anybody else see this specific issue? If I have to take the bumper off to replace a ballast and bulb, then I'm just going to replace both sides. But I want to make sure it isn't something unrelated to the ballast before I buy ballasts...
I have t seen it but as some trouble shooting steps (I know it’s a pain in the arse) swap the bulbs and see if the error moves. Swap the ballasts see if the error moves.


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