Hill descent fault repair

So I'm not sure if you guys have ever experienced issues like this, but I've seen threads of how people would have issues with the "Hill Descent Control Fault" popping up on their dashes randomly and how others would tell them to just clean their high mount brake light. Well I haven't really seen any step by step instructions on how to fix the issue. So as my good deed for the week, I've decided to post a step by step instructions list of how I repaired mine.

So like everyone has stated in threads from the past.... The issue for the hill descent control fault popping up on the dash was due to moisture in the high mount brake light. Mine only happened after a heavy rainstorm. So after a week of rain, I got tired of seeing it pop up every time I started the truck, and not having the ability to utilize my cruise control... So here we go!!!

So this is usually what I would see every time I got in the truck and started it... (ignore the engine light... Already fixed it... Just a faulty thermostat that needed replaced)


First I started by unscrewing the two phillips head screws holding the high mount on to the cab (in the picture you can see the moisture build up in the light).


After removing the screws, it'll pull right off. On the back you can see there's two light bulb connectors (each side) and one LED connection (on the center). To remove the light bulbs, just twist the bulbs a half turn and they will pop right off.


Here is a close up on the LED connector. There's a little tab on the bottom of the connector you have to push in, in order to remove the connector.


After removing the light bulbs and the LED connector, I was able to fully remove the light from the cab and blow it out with the air compressor and let it sit and dry out in the house. Afterwards I sealed the openings with loctite waterproof silicone sealant and let it fully cure so that it doesn't peel off onto the truck.



After drying it out and sealing all the openings, it was ready to be mounted back on to the truck!


So far its been a month since I've fixed this issue and I haven't gotten that problem pop back up! So as for right now I believe it's working!

Hope that this thread has helped you a lot of you how to fix the same issues that you may be having with your raptors! It's a really simple fix and probably took me an hour to do. 45 minutes of it was just to let it air out, seal, and let the sealant cure.

This is my first thread on this site so hope that I have done well enough for you guys to appreciate the post. Thanks guys!

Nice little write up. I'm sure it will be appreciated as the cost of these lights to replace has about doubled in the last year or so! Looks like a cheap little preventive measure to save some cash and headaches!

Thank you. Great write up. Never know.

What exactly did you silicone? What are "the openings"?

I've read it's better to use a butyl rope in place of silicone.

the foam is actually what is sealing the water from getting in. the lens it self is ultrasonically welded to the gray backing part. I'd recommend pulling the foam off, its held on with a thin double sided tape, and either using butyl tape or make another foam gasket. Its not impossible for the lens to have a leak, but its kind of unlikely. you need to fix the seal against the cab.

EricM said:

What exactly did you silicone? What are "the openings"?

I've read it's better to use a butyl rope in place of silicone.

Click to expand...

Sorry, I wasn't very clear on what I meant by opening...

So when I took my high mount brake light off of the cab, mine had a opening between the cover and the backing plate. So no matter how much the foam gasket sealed up against the cab, moisture would still build up inside the circuit board since the openings were on the outside. If you see the picture with the sealant on it, you will see that I used it around the sides to prevent the water from creeping in from the sides. But I also used the black sealant on the foam so that nothing can get inside to the light bulbs.

Hope that kind of cleared it up for you! Sorry again for not clarifying that...

Heres what I did today using morimoto retrorubber. I warmed it up before tightening the screws and wrapped a small piece around each screw. I'm confident it's sealed up good now

downforce137 said:

Heres what I did today using morimoto retrorubber. I warmed it up before tightening the screws and wrapped a small piece around each screw. I'm confident it's sealed up good now

Click to expand...

How difficult or easy will it be to remove the light in the future if you ever needed to?

Jordan@Apollo-Optics said:

How difficult or easy will it be to remove the light in the future if you ever needed to?

Click to expand...

It wasn't very easy, but a little heat from a blow dryer or heat gun and plastic door trim tools got it off.. I found out the next day my vhf antenna was leaking, so had to pull it off and try again... I'm going to look at Home Depot today after work and see what kind of weather stripping options there are. Might be easier

I looked in my owners manual and cannot find anything about any of the P/W specific features. I cant even find anything about the hill descent control. I went to a mountain near me that has a section of unpaved unmaintained road so I could test the 4WD function. The 4WD low range is intense Love it. on the way back down the mountain, I decided to return to 2WD and test the hill descent control. Well; when I was in 2WD; it did not work at all, even with the trans in 1st gear. Does this feature only work when you are in 4WD low range?

Thanks for any info you may have