Think I broke my rear locker. Cruise control stopped working and now the battery is dead

Last night, for reasons that aren't important, I drove on pavement with my rear lockers on and did a half circle while backing out of a spot. There was some grinding but it didn't sound too bad. I turned off 4WD and the locker and drove home. When coasting I could hear grinding coming from what I presume was the rear diff.
Cruise control would turn on but it wouldn't set. Not sure how that's related but it's gotta be right?
I wake up this morning and the battery is just super dead. Not a single light going on.

So I'm very very confused as to what's going on. Any advice would be greatly appreciated

 

Does 4x4 still engage?

Change the battery, might just be timing. The cruise control is likely ran by the computer and without enough battery power might not have wanted to turn on.

Change battery
Check cruise
Check 4x4 engagement

You may have shot your locker but that may tie to batteries somehow too. Someone else can chime in.

just re read and saw something about grinding from the rear diff. Yeah you probably destroyed your locker lol

 

I can still engage 4 high, low, and the diff

The battery is new. Only like 2 months old

It's been on the charger for a while I noticed the break lights are on. I turned the headlights on then off to try to cycle that but it did nothing. This must be why it died over night.

So the truck thinking the brakes are engaged would explain why cruise control wouldn't set. I also tried pumping the brake a few times to no avail. Maybe the grinding was from the brakes being engaged a little bit while I was driving

 

Lift up on the brake pedal and see if the brake lights go out. If they do, you need to adjust the brake light switch. If they do not, you need to unplug the brake light switch and see if they go out.

 

The brake pedal doesn't budge up at all. I'm not sure what you mean by "unplug the brake light switch and see if they go out" Of course if I'm unplugging my brake lights they'll go out. Are you talking about some fuse?

 

The brake light switch is under the dash. It's a spring loaded normally closed switch. When the pedal is up, it pushes the switch, opens the circuit, and the lights are off. When you step on the brakes, the switch plunger moves out and turns on the brake lights. So, 1 of 3 possibilities.
1. When the pedal is all the way up, it's not pushing the switch plunger.
2. The pedal is pushing the switch plunger, but the switch is shot and it's not opening the circuit.
3. You have some other weird problem. Wiring problem, skid control ECU problem, or ???????

 

Ignore that. I looked it up and found what it was. When I got under there I could hear a ringing and as I was trying to unplug it I heard a click like it moved back to where it should be and the lights went off. So that fixes that issue. I let the clutch out while it was in first last night trying to test the 4WD and it jolted forward and I reacted by jamming my foot at the brake. That probably knocked the switch out of alignment or something

Now i'm going to jack up all 4 tires and test my rear locker

 

I wonder if the locker got stuck in the engaged position?

 

I pulled over many times on my way home to turn on and off the locker so I don't think that's it. The brake lights/cruise/dead battery are a separate issue in my mind.

I think I'll jack up the rear tires, put it in first (in 2WD), and just listen to the diff and see if I can hear any grinding

 

So I jacked up the rear in 2WD and only one tire was spinning. I threw it in to first and the same tire (passenger) just spun faster. I don't think that's normal is it?
https://photos.app.goo.gl/5AqXLgTTmg8qtZ6F8

It might not look like it from the video but they are both indeed off the ground
Also I didn't hear any grinding

 

I didn't hear any unusual noise in the video. An open diff will indeed only have one tire spin.

 

Gonna drive it to Oriely's to get a new brake light switch and I'll report back

 

That's not the best thing to do.... Throw your truck in neutral and spin one wheel. If the other side goes backwards you have an open diff. If not you have a LSD. Or you have a broken LSD.

 

My assumption is that someone was drinking and driving last night, or was enjoying life a little too much .

Maybe even both!

Either way, you are toast!

 

Probably a good idea to drain the rear diff fluid and see if you have any unwanted material in it.

 

Alright took it for a drive and the grinding is still there. Only when coasting however. The grinding gets louder when turning and there's a strong burnt popcorn smell. I'm driving it straight to my shop before I ruin something else in my diff

 

Alright apparently I broke a carrier bearing which I guess allowed the rear tire to rub up against the gas tank. $350 for parts and labor. Not too bad

 

Congrats. I hope that does the trick for you.

A couple questions:

Did you replace the brake switch and why?
What’s up w the dead battery? How’d that resolve?

 

How did the tire get to the gas tank? The leaf springs should prevent that since they sit between the tank and tires. Do you have a broken leaf spring that was coming in contact with the tank?

 

I found that the break switch was stuck in the on position so my brake lights were left on all night which killed the battery. I haven't replaced it yet but will this weekend