No power or fob at all

[antsofthesky]

Everything has been great with my 2020 Ram 1500 w eTorque for the last several years.

Suddenly, I go out this am to start it up and I have no unlock, no dash, no nothing.

I test the battery, it pulls back 3.9V -- so way low -- I replace it promptly but I still have no power.

I've checked the ECM fuse (good), I've checked the fuse out terminals (good) and I've checked a few wires that seem ok despite there being some dander (pollen and debris) in the crevices. I think a mouse may have made home for a little bit but it doesnt seem like there's been any major damage.

What am I missing?

 

[vincentw56]

Everything has been great with my 2020 Ram 1500 w eTorque for the last several years.

Suddenly, I go out this am to start it up and I have no unlock, no dash, no nothing.

I test the battery, it pulls back 3.9V -- so way low -- I replace it promptly but I still have no power.

I've checked the ECM fuse (good), I've checked the fuse out terminals (good) and I've checked a few wires that seem ok despite there being some dander (pollen and debris) in the crevices. I think a mouse may have made home for a little bit but it doesnt seem like there's been any major damage.

What am I missing?

Sounds like the RF hub. Do you the rear window leak? This all over this forum if you search.

 

[Stock4Now]

Thread 'Module under rear panel failed, car won't start, window leak'

Feb 21, 2025

Hello,

Had to tow my truck to the dealer due to this issue that is supposedly common. I'm hoping someone could post me to a master thread on this topic. Truck is ~4 months out of the 3 year/30k bumper to bumper warranty. Has anyone had success with Ram still covering this? Why hasn't it been issued as a recall if it's such a common issue?

Thanks for the help. Hoping not to have to pay out of pocket for this fix.

• sessman
• Replies: 11
• Forum: 5th Gen General Discussion

2021 Ram 1500 Big Horn 4x4 North Rear Window Leak

 

[Keezer]

I agree, RF hub.
Is @RamCares still around? I have about the same issue (2020 Laramie) no cracks on the window frame, looks like it may crack but been that way for 5 years. Bet they say water though, best to get yours to a dealer (hopefully a good one) to diagnose, if the RFhub is not talking to the fob you may not be able to get it into neutral even by pulling the rip cord.
Makes towing in all that much more fun. Dealer may be frustrating as they will start with the battery even though in my case remote start works then go from there, probably take em a week or more to check everything, seems RFhub and Can Bus is last on the list.

Good luck and please let us know what you find.

 

[antsofthesky]

WOW, ok. So you won't believe what this was... I took apart the ENTIRE battery housing -- it had collected lots of water in and around it. I look around at the wires, at this point, it was the last gremlin to chase.

Solid amount of bitemarks, scratches, and tears by the wire cluster leading to the fuse box and another tucked under the upper fender.

I just spent the last 2 hours rebuilding the wiring harness. I guess there are big benefits to having your own electronics manufacturing facility... I don't believe this fix would be available to any/all regular folks. Smh. Are these harnesses using a corn or soy based plastic?

 

[vincentw56]

Are these harnesses using a corn or soy based plastic?

Are you asking because something chewed the wires? I've seen mice and rats chew on anything and everything. It doesn't matter what it's made of, except metal.

I'm glad to hear you found it and fixed it, and I'm glad to hear it didn't screw up anything else.

 

[Keezer]

Soy based wires, rodents love em, my rodent got on top of the intake and chewed the wire to the MDS solenoid.
Good ya found it and can fix it, good job getting it figured out!

 

[antsofthesky]

Are you asking because something chewed the wires? I've seen mice and rats chew on anything and everything. It doesn't matter what it's made of, except metal.

I'm glad to hear you found it and fixed it, and I'm glad to hear it didn't screw up anything else.

Agreed on mice and rats -- but this was clearly squirrels as there were acorns stashed about. I'd like to know in case this becomes an ongoing issue.

 

[vincentw56]

Agreed on mice and rats -- but this was clearly squirrels as there were acorns stashed about. I'd like to know in case this becomes an ongoing issue.

That's nuts.

 

[antsofthesky]

I, uh, see what you did there...

Anyway, thank you all for your help!