N3 Fuse Blown

[bettywhitewoods19]

Wanted to post here and see if I can maybe get any answers or some help in the right direction. Almost a month ago it got pretty cold in southern DE and my 2019 wrangler’s center cluster went blank. No warning, no dullness to the light when it was on prior, nothing. I really gave the jeep the benefit of the doubt due to the cold and figured it’d warm up the next day and it’d be back on. Wrong. I drove it up the road for about 10 minutes and still did not turn on. Parked it for the weekend. I got in on a Monday morning to head to work, still no center cluster screen and the jeep started going “crazy.” Lights came on the left side cluster and throughout the dash, the heat controls were going up and down, my windows rolling up very slowly, I turned the jeep off.

I went out later on in the day and started it back up and the jeep essentially went haywire. Lights flashing again across the dash, reving of the engine without pressing the accelerator, air controls going up/down, and windshield wipers. One of my relays under the hood was clicking after shutting the jeep off after this and disconnecting the battery. Did some research and replaced the can bus connector. Trickle charged the battery just in case due to the cold. Jeep won’t turn on at all. No interior lights when doors are engaged, nothing. I think I’ve narrowed it down to the N3 fuse located to the side of the fuse box. I personally want to know if this is the right direction I’m headed or if anyone else has experienced something similar at all to this. Any info is appreciated.

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[The Last Cowboy]

I'd look more towards the CANbus star connector behind the glove box. If it starts and drives, I doubt it's high amp fuse array.

 

[alphawolff]

Wanted to post here and see if I can maybe get any answers or some help in the right direction. Almost a month ago it got pretty cold in southern DE and my 2019 wrangler’s center cluster went blank. No warning, no dullness to the light when it was on prior, nothing. I really gave the jeep the benefit of the doubt due to the cold and figured it’d warm up the next day and it’d be back on. Wrong. I drove it up the road for about 10 minutes and still did not turn on. Parked it for the weekend. I got in on a Monday morning to head to work, still no center cluster screen and the jeep started going “crazy.” Lights came on the left side cluster and throughout the dash, the heat controls were going up and down, my windows rolling up very slowly, I turned the jeep off.

I went out later on in the day and started it back up and the jeep essentially went haywire. Lights flashing again across the dash, reving of the engine without pressing the accelerator, air controls going up/down, and windshield wipers. One of my relays under the hood was clicking after shutting the jeep off after this and disconnecting the battery. Did some research and replaced the can bus connector. Trickle charged the battery just in case due to the cold. Jeep won’t turn on at all. No interior lights when doors are engaged, nothing. I think I’ve narrowed it down to the N3 fuse located to the side of the fuse box. I personally want to know if this is the right direction I’m headed or if anyone else has experienced something similar at all to this. Any info is appreciated.

n3 fuse blowing is very, very common. just replace it and both batteries.

 

[SadRobot]

Wanted to post here and see if I can maybe get any answers or some help in the right direction. Almost a month ago it got pretty cold in southern DE and my 2019 wrangler’s center cluster went blank. No warning, no dullness to the light when it was on prior, nothing. I really gave the jeep the benefit of the doubt due to the cold and figured it’d warm up the next day and it’d be back on. Wrong. I drove it up the road for about 10 minutes and still did not turn on. Parked it for the weekend. I got in on a Monday morning to head to work, still no center cluster screen and the jeep started going “crazy.” Lights came on the left side cluster and throughout the dash, the heat controls were going up and down, my windows rolling up very slowly, I turned the jeep off.

I went out later on in the day and started it back up and the jeep essentially went haywire. Lights flashing again across the dash, reving of the engine without pressing the accelerator, air controls going up/down, and windshield wipers. One of my relays under the hood was clicking after shutting the jeep off after this and disconnecting the battery. Did some research and replaced the can bus connector. Trickle charged the battery just in case due to the cold. Jeep won’t turn on at all. No interior lights when doors are engaged, nothing. I think I’ve narrowed it down to the N3 fuse located to the side of the fuse box. I personally want to know if this is the right direction I’m headed or if anyone else has experienced something similar at all to this. Any info is appreciated.

Have you tried moving the cable from N3 over to N4? If N3 is blown then moving it over should start up the Jeep just fine. Then you can just replace the fuse array.

 

[Badunit]

Your problem sounds like low voltage.

Looking at the wiring diagrams for a 2023...
N3 is the fuse that connects the positive of the main battery to the positive of the aux battery via the Power Control Relay. Without it the Aux battery cannot charge. Without it, the voltage at N1 (which is fed by the aux battery) will decline as the aux battery dies. N1 feeds a lot of electronics.

A bad power control relay would act the same as a blown N3 fuse.

After being off the charger and engine not running for a while,

1. Check voltage at N1. This is the aux battery
2. Check voltage at N2. This is the main battery.
3. Either one low means bad battery. One battery going bad will draw down the other and kill it (assuming fuse N3 is good and the relay is good).
4. N1 and N2 should be the same if fuse N3 and the power control relay are okay.
5. If N1 is lower by a wide margin, either the fuse or relay may be bad

 

[ScotM]

N3 usually blows when disconnecting the battery, and not separating the aux out of the system, so then the negative battery cable hits something and shorts out the N3.

 

[Badunit]

Is it that or when the main positive cable touches ground, or the wrench touches ground. We are all conditioned from years of 1-battery systems to think once the negative is off, the positive is safe/cold, but with our 2-battery system, the positive cable is still hot. Current would go from aux positive post ->Power control relay->N3->N3 fuse->N2->main positive cable->ground = poof. Right?

 

[ScotM]

If you need to remove the fuse array, I’ve found the easiest way to lift it off is either a zip tie

 

[ScotM]

Is it that or when the main positive cable touches ground, or the wrench touches ground. We are all conditioned from years of 1-battery systems to think once the negative is off, the positive is safe/cold, but with our 2-battery system, the positive cable is still hot. Current would go from aux positive post ->Power control relay->N3->N3 fuse->N2->main positive cable->ground = poof. Right?

If the aux is connected, and the negative cable from the main touches ground of the jeep, it can short the N3, because the negative is still connected to the aux. it’s confusing, but anytime working on the jeep both the negative cables need to be separated and care must be taken to ensure nothing shorts out.

 

[alphawolff]

dont overthink it just pull the fuse array and check it lol takes 5mins

 

[ScotM]

dont overthink it just pull the fuse array and check it lol takes 5mins

That is very true, I was just trying to help with how it may have blown, so it doesn’t happen again.

 

[alphawolff]

That is very true, I was just trying to help with how it may have blown, so it doesn’t happen again.

ive seen most just blow during a stop/start event. engine shuts off then doesnt come back on.

 

[ScotM]

ive seen most just blow during a stop/start event. engine shuts off then doesnt come back on.

Interesting, I’m just a root cause kind of guy. I mean, could be a crappy latent defect in the fuse array, but something causes it.

I blew mine by not understanding the aux battery still powering the jeep after I disconnected the negative battery cable. Now I’ve ripped out all the cabling and the aux battery, and killed the start stop

 

[alphawolff]

Interesting, I’m just a root cause kind of guy. I mean, could be a crappy latent defect in the fuse array, but something causes it.

im leading towards defect personally, i see too many and we just replace batteries + array and they never come back

 

[bettywhitewoods19]

ive seen most just blow during a stop/start event. engine shuts off then doesnt come back on.

My main and aux battery were replaced about 3 1/2 years ago. I had the aux battery die on me at a stop light with the start/stop system engaged, locked my front & rear up and cost me about $700 at the time.

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