RAM 4WD SERV Light & Tips on Drive It or Not 

**Update** After driving an additional 900+ miles I finally got home and took my truck to the RAM dealer. Quote from tech "Inspection found C147B, performed diagnostic, confirmed Front Axel Disconnect (FAD) hanging up. Removed and replaced Front Axel Disconnect." Hope this helps if anyone is having these issues.

I really appreciate you posting this. I just had to switch into four-wheel drive for the first time since owning my 2017 Ram 3500 dually after picking up my 4500 lb slide in camper that's sitting in the back. I'm in the mountains of North Carolina when this happens and I did smell something strange coming from up in the engine compartment when that light came on after driving it down the mountain another 5 mi or so to a safe stopping point. The smell seems to have gone away but it does not appear to want to engage four-wheel drive lock or four-wheel drive low no matter what buttons I push or which selector position on the dial I choose. I'm definitely going to stop messing around with it because I've got another 1300 mi to go back to Houston. Driving right now as I type with a 4WD SERV yellow lamp indicator. Obviously your advice is just a tip but I was going to keep driving anyway so I'm glad to see that you posted your experience from talking with them.

Great video and info. Hate those intermittent issues like that.

You saved my life!! thank you!!!!

Had a similar issue. Originally surfaced while towing a 5th wheel on the I-75 Macon GA by-pass. Based on net search I checked my fuses and found all of them not fully seated. Pushed them in about 1/4 inch. That cleared the issue. Drove another 1200 miles and the same condition occurred after driving the I-75 by-pass in Macon. Stopped at a rest area and found the same condition. After pushing them back in...no more issues (probably until I tow back through Macon). Don’t know if there’s a resonance in the road surface or what...but will continue to monitor for recurrence and update if it happens without driving on that particular segment of road.

Great info. Thanks

Update. Replaced mine with a part from Amazon and it failed in 400 miles. It was full of water inside the electronics control board portion of it. This made me pull apart the original OEM won that failed at $98,000 mi and it two had water penetration because the control board was corroded in the corner where there was nothing to cause corrosion other than water intrusion. Tonight I received a free replacement part from the same Amazon vendor, used painters tape to seal off the electrical connector portion, used a plastic bag and painters tape to seal off the portion that mates to the axle and liberally sprayed three separate coatings of Rust-Oleum rubberizing flexible waterproofing aerosol sealant made for roofs, non-pressurized water fittings and basically anything else you need waterproofed that does not have pressure inside of it. I guarantee this stops these failures

Superb video 👌🏽👌🏽💪🏼

Great video! This is what youtube is supposed to be like!

Bless thank you

I live near Crystal River & there are 2 Ram dealers I use nearby. Plaza Ram in Inverness & Phillips Ram in Ocala.

Good info, thank you. Informative.

Maybe I missed it but I thought you were going to say something about your blue driver. I have been looking for an OBD reader but most adds dont specifically say diesel. Thanks

Mine actually will go into 4 wheel drive high on it's own, too.

Watt do you fix in you pick up I have one 2014 dodge Ram 3500 hundred single wheel and I have the light 4WD serv yellow letter watt do you fixed

Just had this happen on a 18 3500 , batteries were weak. Replaced batteries problem solved.

Well, my 2016 Ram 1500 Big Horn did leave me on the side of the road. I got where I was going and when I came back out the truck would not start and the 4 WD light was RED! There was a fluid on the asphalt that may have bee from the truck, but here I am, with the Quirk Dealership in Quincy, Massachusetts telling me that they are our 10 days for service APPOINTMENTS. Sounds pretty scummy to me! I'll try to get the actuator replaced or at least serviced from a regular mechanic, but I'm starting to lose confidence in Ram!

There is a top notch Ram tech at Key West

Great video, thanks for it. I have a 2011 3500 6.7 Cummins, same light recently. I thought it might be a service reminder to change differential and transfer case fluids. Will go get my codes checked, or maybe buy the OBD reader you like. And the dealership? What a joke. Thanks for info, and continuing safe travels!

Was it windy when it came on? Mine came on when it was -35 below. But you are in Florida. So idk..

Have had the same issue... only when I pull my camper long distances. Axle disconnect has been changed 3 times, and I am about to take it in for the 4th time with only 50k miles on truck. So hope your repair lasts longer than mine. I am curious if you have been able to pull camper on long trips before with no issue?

I just had the air conditioning fixed at a local repair shop and when I picked it up the serv 4WD was on , they had dash out on my 2011 Ram I hope they forgot to hook up a wire ? What do you think ?

Mine turned on and off today. While googling I watched this and figured out my problem. Service 4wd turned on then off while in the carwash with undercarriage spray. Must have gotten the actuator plug wet since I haven't seen it since.

I’ve got a 2015 Ram 3500 that’s been having the service 4wd system message pop up intermittently on the screen. I’ll have to use my code reader and see what codes are popping up with the message. It’s really discouraging to hear of yet another Dodge dealership that’s pretty much worthless and has terrible ratings. You’d think Chrysler/Dodge would hold dealerships like this accountable, instead us customers have to tolerate them.

My 14 1500 has done this but is stuck is 4wd could it be the same?

My 2014 dodge ram 1500 wont start. I have a 4WD SERV message along with message in regards to my breaks. Why won’t my truck start?

Thanks, what happened when you service, my still under warranty, only 7500 some miles.

Love your videos but there isn’t anyway I’d trust a Dodge/Chrysler/Fiat/Jeep product. I pull my Airstream with a 2021 Toyota Sequoia Platinum 4WD……. Too many trusted mechanics I know and former owners have told me horror stories of these typically defect ridden products. Resale tells the tale too. So sorry for your headaches. Trade it for a Tundra would be my next move.

You talk to much just get to the damn point

No diagnostic/repair value to this video. Thanks anyway.

And just subscribed!

I just needed information on why the light keeps coming on and not all this blathering on this video sucks