Help: Tail lights don't turn on with headlights!

[makeamericagreenagain]

Noticed this today after someone flashed their brights at me but am not sure how long this has been going on. It appears my tail lights are not turning on with headlights. Brake lights seem to function as designed.

I'm assuming this is a blown fuse but after looking at the user's manual I can't seem to determine which fuse would control this. Any help or am I going to have to pull one fuse at a time? Or is this something else I'm not aware of?

 

[KentuckyKen]

Noticed this today after someone flashed their brights at me but am not sure how long this has been going on. It appears my tail lights are not turning on with headlights. Brake lights seem to function as designed.

I'm assuming this is a blown fuse but after looking at the user's manual I can't seem to determine which fuse would control this. Any help or am I going to have to pull one fuse at a time? Or is this something else I'm not aware of?

There are 3 fuse boxes under the hood and 4 under the dash (pp 553-559 in the US manual).
Unfortunately the abbreviations are so cryptic that I couldn't tell which fuse protects the taillights and my usually potent Google-fu failed me, so I resorted to turning on the parking lights and taking out fuses one by one until they went off. Strangely enough, all the parking lights are protected by fuse #21 in fuse box A (the big one under the hood to passenger side) that is marked BACK UP. Go figure?!?
If you take the cover off, it will have a fuse puller and some spare fuses under the cover itself. Try replacing it with the same size 10 Amp spare.
Fuse 21, BACK UP, is a 10 Amp that I circled in red in the picture below. Let us know if it was blown and if a new fuse fixed it or you had to go to the dealer.

 

[jdonalds]

There are 3 fuse boxes under the hood and 4 under the dash (pp 553-559 in the US manual).
Unfortunately the abbreviations are so cryptic that I couldn't tell which fuse protects the taillights and my usually potent Google-fu failed me, so I resorted to turning on the parking lights and taking out fuses one by one until they went off. Strangely enough, all the parking lights are protected by fuse #21 in fuse box A (the big one under the hood to passenger side) that is marked BACK UP. Go figure?!?
If you take the cover off, it will have a fuse puller and some spare fuses under the cover itself. Try replacing it with the same size 10 Amp spare.
Fuse 22, BACK UP, is a 10 Amp that I circled in red in the picture below. Let us know if it was blown and if a new fuse fixed it or you had to go to the dealer.
View attachment 5891

Nice work Ken.

 

[KentuckyKen]

Nice work Ken.

Thanks.
Sometimes if you’re not smart enough to figure it out you can just brute force it.
Kind of like this approach:


I forgot to add that if only the tail lights are out, then it’s probably not fuse related (since they are all on one fuse) and may be a wiring/connector issue going to the rear. And if only one tail light is out it’s probably an LED/connector/wire issue on that one side.
PS:
My trusted local mechanic says tracing down wiring problems, especially intermittent ones, are the hardest and least liked problem he has to deal with. So if it’s not a fuse bring your mechanic some cookies or doughnuts!

 

[MrFixit]

In the old days, the dash panel lights were usually on the same circuit as the tail lights.
That way, you knew immediately when your tail light circuit had a problem.
Electronic dashboards have changed that forever.

 

[makeamericagreenagain]

There are 3 fuse boxes under the hood and 4 under the dash (pp 553-559 in the US manual).
Unfortunately the abbreviations are so cryptic that I couldn't tell which fuse protects the taillights and my usually potent Google-fu failed me, so I resorted to turning on the parking lights and taking out fuses one by one until they went off. Strangely enough, all the parking lights are protected by fuse #21 in fuse box A (the big one under the hood to passenger side) that is marked BACK UP. Go figure?!?
If you take the cover off, it will have a fuse puller and some spare fuses under the cover itself. Try replacing it with the same size 10 Amp spare.
Fuse 21, BACK UP, is a 10 Amp that I circled in red in the picture below. Let us know if it was blown and if a new fuse fixed it or you had to go to the dealer.
View attachment 5891

Wow, thanks Ken, that’s above and beyond what I was expecting. Unfortunately swapping the fuse doesn’t seem to have fixed the problem so I’m dropping it off at the dealer today. I’ll post an update.

 

[Sandroad]

Very odd failure! If you had not mentioned reading the owners manual I would have asked if you were certain the light switch was in the correct setting, or if there were any differences in what lights worked based on switch position. I’ll be interested in the dealers report.

 

[makeamericagreenagain]

Very odd failure! If you had not mentioned reading the owners manual I would have asked if you were certain the light switch was in the correct setting, or if there were any differences in what lights worked based on switch position. I’ll be interested in the dealers report.

Tail lights don't come on regardless of light switch position (parking, auto, lights on). They appear to be the only lights affected--DRLs and parking lights (I think that's what they're called, the yellow ones on the outside edge of the headlights) are working properly.

One other detail that I'm realizing might be relevant is that my wife had a minor fender bender ~2 months ago and crunched in the front bumper a pretty small amount. Haven't taken it to the body shop yet because it was so minor. Perhaps some wiring was disrupted? No damage to the back of the vehicle.

Will update as I hear from the dealer.

 

[David in TN]

There are 3 fuse boxes under the hood and 4 under the dash (pp 553-559 in the US manual).
Unfortunately the abbreviations are so cryptic that I couldn't tell which fuse protects the taillights and my usually potent Google-fu failed me, so I resorted to turning on the parking lights and taking out fuses one by one until they went off. Strangely enough, all the parking lights are protected by fuse #21 in fuse box A (the big one under the hood to passenger side) that is marked BACK UP. Go figure?!?
If you take the cover off, it will have a fuse puller and some spare fuses under the cover itself. Try replacing it with the same size 10 Amp spare.
Fuse 21, BACK UP, is a 10 Amp that I circled in red in the picture below. Let us know if it was blown and if a new fuse fixed it or you had to go to the dealer.
View attachment 5891

Ken, you need to turn the fuse back. It is upside down. This means that your taillights might be on all the time!!! [emoji23][emoji1787][emoji23]

Sent from my SM-N960U using Inside EVs mobile app

 

[Notmyrealname]

Tail lights don't come on regardless of light switch position (parking, auto, lights on). They appear to be the only lights affected--DRLs and parking lights (I think that's what they're called, the yellow ones on the outside edge of the headlights) are working properly.

One other detail that I'm realizing might be relevant is that my wife had a minor fender bender ~2 months ago and crunched in the front bumper a pretty small amount. Haven't taken it to the body shop yet because it was so minor. Perhaps some wiring was disrupted? No damage to the back of the vehicle.

Will update as I hear from the dealer.

What was the resolution of this issue? I just had my AC condenser replaced and just now noticed that my taillights are no longer working. Wondering if they damaged some wiring during the AC repair.

 

[makeamericagreenagain]

Should have replied earlier! There is a wiring harness right up by the front bumper that ended up being the culprit. I believe the tech said something like an in-line fuse needed replacement. It was damaged in my case by a very minor front end collision. Very likely a wiring issue if you are having the same problem.

 

[Notmyrealname]

Should have replied earlier! There is a wiring harness right up by the front bumper that ended up being the culprit. I believe the tech said something like an in-line fuse needed replacement. It was damaged in my case by a very minor front end collision. Very likely a wiring issue if you are having the same problem.

Thanks! That’s good to hear. Hopefully it’s just something they forgot to reconnect in my case.

 

[ZDub77]

Should have replied earlier! There is a wiring harness right up by the front bumper that ended up being the culprit. I believe the tech said something like an in-line fuse needed replacement. It was damaged in my case by a very minor front end collision. Very likely a wiring issue if you are having the same problem.

I know this is old, but any information other than "in-line fuse"?
I am in a similar situation where someone side-swiped the driver's front bumper, causing very little damage, and now the rear lights do not come on with the headlights. The paint and body shop says it is unrelated because all the front lights are still working. I poked around up there for an hour or so and could not find any fuse.

 

[MrFixit]

I poked around up there for an hour or so and could not find any fuse.

There is something that is referred to as an "Auxiliary Under Dash Fuse Box".
I am not certain where it is exactly, but here is a figure that depicts it:


Here is a list of the functions of these fuses:



Note that F4 is the relevant fuse for the taillights, HOWEVER, it looks like a lot of other things would also be out if this fuse were bad, so unfortunately this is not likely to be your problem. I posted this information mostly for general reference.

 

[ZDub77]

There is something that is referred to as an "Auxiliary Under Dash Fuse Box".
I am not certain where it is exactly, but here is a figure that depicts it:

View attachment 20219
Here is a list of the functions of these fuses:
View attachment 20220
View attachment 20221

Note that F4 is the relevant fuse for the taillights, HOWEVER, it looks like a lot of other things would also be out if this fuse were bad, so unfortunately this is not likely to be your problem. I posted this information mostly for general reference.

Thank You! This was my problem, and a fuse that I didn't check due to it not having any description I found for tail lights. I guess I didn't know the side marker lights, among other things, were out too. I feel dumb, but I am very glad to have it fixed! If you ever make it to the Triad area of North Carolina, I owe you a beer.

 

[MrFixit]

If you ever make it to the Triad area of North Carolina, I owe you a beer

Glad the information helped...
Would you care to elaborate on precisely where this Aux fuse panel is located for future reference?

 

[Thomas Philipp]

In the owner's manual, I think it is Fuse Block "C", the bottom fuse. Mine keeps blowing, found after an hour on the phone with Honda Customer center, nobody knows the meanings of some of the designations. I think the manual says "small". Anyway, anybody have anything further on the inline fuse location, up-front that might be causing this? Thanksl

 

[MrFixit]

In the owner's manual, I think it is Fuse Block "C", the bottom fuse

Your message is a little unclear...
On the one hand, you say it "keeps blowing" as though you know the location if the fuse and have already tried replacing it..
On the other hand, you are asking about the location of the fuse.

Do you know where the fuse is, and are asking why it might be blowing, or do you not even know where to look for the fuse?

 

[Landshark]

In the owner's manual, I think it is Fuse Block "C", the bottom fuse. Mine keeps blowing, found after an hour on the phone with Honda Customer center, nobody knows the meanings of some of the designations. I think the manual says "small". Anyway, anybody have anything further on the inline fuse location, up-front that might be causing this? Thanksl

You will most likely be chasing your tail by looking for a fuse that is causing another fuse to blow. Excessive current is what causes a fuse to blow. A short circuit or water intrusion are possibilities.

As you’ve experienced, replacing a fuse without identifying the fault will result in another blown fuse. The fuse is protecting components from potential harm.

 

[Thomas Philipp]

This thread started with no one knowing the "parking light" fuse location, that is what I was identifying in the C fuse block. My question was in regards to follow up posts regarding front end damage causing an inline fuse to cause the overall problem. I was going to unplug the front marker lights and see if this stopped the C block fuse from blowing but just moving all the wires attached to the marker lights seemed to have fixed my problem. Sorry for the confusion.