Drivers Tail Light Running Lights Not Working

[AvockAdoo]

Good job chasing it down.

Did Morimoto cover the headlights?

Yes - I cant say negative things about them as a company. The rush shipped new lights to me and gave me 6 weeks to install them. Really Class 1 customer service.

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[AvockAdoo]

This is more or less the same reason I had to switch my fancy sequential lights I put on the rear of my rack. I had them wired directly into the tail light harness because tapping the trailer harness made my fancy sequential turn signals blink normal instead of... you know the nice looking sequential sequence.

For an entire year they worked fine, then suddenly one day my driver side (only) started causing a fast turn signal blink. My factory signals were fine, but it was acting like I had a bulb out somewhere and my driver rear rack sequential no longer worked. I re-wired to some beefier ground spots and did what I thought was a BCM reset. Worked fine, for about a week, then reverted.

I gave up trying to chase the tail of the dragon and re-wired to my trailer harness wiring, opting to get functionality back vs. fancy sequential. The added benefit is I could reduce the system down to 3 wires, instead of 5.

All that to say this; why a simple electrical system such as turn signals needs to be tied to a fancy computer system is stupid.

Edit: One day I am going to try a last ditch effort and not only move the wiring to a relay, but also add a one way diode into the circuit to see if I can get my sequentials back.

I completely agree. It should be a simple system, they're damn tail lights. I understand the need for BLIS in them, etc.. which has helped me on a fair few occasions, but lets keep things simple, PLEASE.

 

[OFC Ranger]

I completely agree. It should be a simple system, they're damn tail lights. I understand the need for BLIS in them, etc.. which has helped me on a fair few occasions, but lets keep things simple, PLEASE.

If I had known what BLISS was I probably would have opted for a Ranger with standard non-LED tail lights then just upgrade them myself via aftermarket bulbs.

I'd swap out to non-BLISS tail lights now, but the whole system is integrated and it would be a PITA to disable it so Im not getting constant dash warnings.

 

[Xwaz]

I'm having troubles with my tail lamps too. My rear brake lights stay lit when the running lights are turned on. (LED Lariat) I removed all the wiring from the cap and I disconnected the battery twice but not for over 5 minutes. Going to try again for longer period of time and see if it resets the BCM.

That's the same issue that I am having. Brake lights remain on when the running lights are on. Mine seems isolated to when the auto headlights come on and at night. However after 30 minutes or so of driving the driver side Amber for the blinkers gets stuck on and I get a hyper flash on the cluster.
Xlt with Led taillights, all lights are factory and nothing has ever been tapped into them .

 

[AvockAdoo]

That's the same issue that I am having. Brake lights remain on when the running lights are on. Mine seems isolated to when the auto headlights come on and at night. However after 30 minutes or so of driving the driver side Amber for the blinkers gets stuck on and I get a hyper flash on the cluster.
Xlt with Led taillights, all lights are factory and nothing has ever been tapped into them .

Have you swapped to LED bulbs or anything like that, or is it all 100% stock? I'd bet theres a wiring issue for you. Take it to ford specially if you're under 3/36 (or whatever your warranty was/is). I ended up getting rid of my ranger (in part) because of my electrical issues. I started having them diagnosed at 20k miles, and they could never "find anything" until I was over my warranty, and then they wanted $450 to run an electrical diagnostic and wouldnt cover the pre existing issues that were documented under warranty. I LOVED my Ranger. Most fun vehicle I've ever owned, but Ford's service made the thing undesirable to own. I dont have enough money to own a Ford truck, so I had to go get a slow, boring toyota.

 

[Xwaz]

Have you swapped to LED bulbs or anything like that, or is it all 100% stock? I'd bet theres a wiring issue for you. Take it to ford specially if you're under 3/36 (or whatever your warranty was/is). I ended up getting rid of my ranger (in part) because of my electrical issues. I started having them diagnosed at 20k miles, and they could never "find anything" until I was over my warranty, and then they wanted $450 to run an electrical diagnostic and wouldnt cover the pre existing issues that were documented under warranty. I LOVED my Ranger. Most fun vehicle I've ever owned, but Ford's service made the thing undesirable to own. I dont have enough money to own a Ford truck, so I had to go get a slow, boring toyota.

Mine lights wise is 100% stock. Only thing being Bambi mode being programmed on.

However I did find what I believe to be the issue and it might help others. The next post will be my findings.

 

[Xwaz]

Here are my findings on my 2020 Ranger XLT.
Lights are 100% stock. Halogen headlights, with factory LED Taillights.
Issues: over about a week I had an issue where the brake light portion of the taillight would stay one whether the brake pedal was pressed or not.
I also had an issue where the Amber turn lamp would get stuck on throwing a fast flash blinking. This happened twice after driving for about 30 minutes.
Forscan had these codes:
BdyCM B1265:01-08
Left rear turn lamp feedback
-general electrical failure


FCIM B113C:11-48
Hazard switch illumination
Circuit short to ground

Based on that is seemed that it was a physical issue and not computer related.

I had tried clearing codes as well as disconnecting The battery for 30 minutes with no results.

While I have not done enough testing to prove it's the solution but I believe these could be the cause of my issues and possibly others.

I inspected the plugs that are on the frame behind the rear wheels, these attach outside the frame and are there for the taillights and being able to remove the bed.
I found that my driver side plug was full of water. About a tea spoon of water came out once opened.

This very likely was caused by the recent extreme cold snap we had here in Colorado. And the snow lasting for a few weeks. I believe that over time this plug just gets pelted by snow and ice, and through freeze thaw cycles there is a small chance of water ingress.

I blew It out with compressed air, cleaned it with electronic connector cleaner, and filled the connector with dielectric grease to create a water proof seal.
I tested again and had no codes and after about 35-40 minutes that night, the lights all functioned perfectly.


I would be curious if those others having similar issues if they checked these plugs to see if there was any evidence of water ingress causing a short.

 

[Xwaz]

To provide and update, a couple weeks on.
Everything is working exactly as it should, we have had warm weather, snow, sub zero weather in that time, I have driven for a couple years at a time. They are back to normal functionality. So I can say that it was the water getting into the connector that causes my Taillight issues. Worth checking for those experiencing a similar issue.

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