Blew vehicle fuse, still not working

markr6

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Here's what happened to my 2015 Jeep Grand Cherokee recently:

1. I ran a tire pump (too long) and it finally died. Figured it was the pump. Turned out to be the fuse since two of the cigarette lighters stopped working.
2. Replaced the blown 20A fuse.
3. Front cigarette lighter started working again. But cargo area did not (the one used to run pump).

So any ideas? All the fuses are good now. Still no power to the port in the cargo area.
 

raggie33

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fuse are to protect wireing and devices im guessing maybe a wire or connecter bit the dust
 

markr6

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fuse are to protect wireing and devices im guessing maybe a wire or connecter bit the dust


So in this case the damage possibly occurred before the fuse could protect it? I see there are replacement sockets. Maybe I'll try that for $10.
 

badtziscool

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Could be that the wiring to the rear socket overheated and caused a short and the short was what blew the fuse, so it could be anywhere in between the first and second socket.
 

markr6

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Could be that the wiring to the rear socket overheated and caused a short and the short was what blew the fuse, so it could be anywhere in between the first and second socket.


Sounds like fun digging behind those panels! Hopefully I can figure out how to open the cargo area and maybe find something there. At least the front socket is working now. I use that a lot for charging my phone.

Thanks!
 

badtziscool

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Sounds like fun digging behind those panels! Hopefully I can figure out how to open the cargo area and maybe find something there. At least the front socket is working now. I use that a lot for charging my phone.

Thanks!

Yeah, I'm thinking it's going to be somewhere near or at the rear socket considering that's where the crimps, connections, and corrosion are. Just don't be surprised if it's somewhere in between.

Good luck!
 

louie

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I'm wondering if you might have fusible links in your wiring harness to the rear. If you had a wiring diagram, a little voltmeter work would help you isolate the problem. You could get lucky by just pulling out the dead socket, and seeing if the wiring there looks OK.
 

turbodog

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I'm wondering if you might have fusible links in your wiring harness to the rear. If you had a wiring diagram, a little voltmeter work would help you isolate the problem. You could get lucky by just pulling out the dead socket, and seeing if the wiring there looks OK.

Have never seen fusible links for such low amp wiring. But I agree... pull the socket and check it carefully.

This tool is useful for checking wiring. Very quick. Just jab it through the insulation.

https://www.amazon.com/Voltage-Continuity-Current-Tester-Indicator/dp/B01BGZ9XRS/ref=pd_lpo_263_t_1/140-1247546-8736524?_encoding=UTF8&pd_rd_i=B01BGZ9XRS&pd_rd_r=abfba53f-dd33-4a1a-b153-cd7e7466fa8a&pd_rd_w=5znNW&pd_rd_wg=5feT9&pf_rd_p=7b36d496-f366-4631-94d3-61b87b52511b&pf_rd_r=3ME8AFX9X359A5STGBJ3&psc=1&refRID=3ME8AFX9X359A5STGBJ3
 

bykfixer

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I would check the owners manual for fuse locations and what circuit does what. There's a good chance there is another fuse upstream such as under the hood or at the kick panel by the door.

Check to see if anything else does not work. A clock, another 12 volt port or that type of thing that should be identified in the fuse map in the owners manual.

If that is the only thing not working, unfortuneatly you may have to find where it begins and check the circuit from there to the actual port itself. Blowing a 20 amp fuse means something serious took place. Whatever went wrong may have cooked the port at it's connection. That would be the best case scenario. Or it could be another fuse upstream blew as well.

A digital volt meter set for ohms with sound activated can assist. Using the pins instead of clips, you poke a positive probe at the source and the negative when touching wire will chirp where you have electrical flow. Start a few inches away from the plug and if you get a chirp you know the issue is the plug. If you don't get a chirp find the other end of the wire and check that. If you don't get a chirp there the problem isn't just the wire that supplies current to that 12 volt plug.

Best of luck. Electrical woes are such a drag.
 
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orbital

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I know this sounds really negative, but I don't mean for it to be.

Personally, I'd stop using that outlet all together, because there may be compromised wiring upstream from that point.
Do you want to replace w/ another '15A' outlet that uses a 20A fuse?

Let's say you replace the outlet because its what failed,, what are you going to run confidently in that outlet later on?

_______________________________________________
btw: I had a '93 Grand Cherokee Laredo.
 
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markr6

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This one is kinda unique because the fuse can be moved slightly to another slot to make it function either as an "accessory" or "full time" (car off). So the vehicle doesn't need to be set to "Accessory" with the key to provide power. Not that it matters in this scenario (I think).

The schematic says that's all the 20A fuse does. Also the 120v inverter, but I'm not fancy enough to have that option in mine.

I could probably get away with never using this one again. The few times I used it was for topping off a tire. I can reach all tires from another port in the front.

I wonder, would I have been OK running this pump with the engine running...to provide more voltage? I see some manuals say that, including the new pump I just bought.

p.s. I guess I ran the pump too long. I had a flat, so going from ~2psi to 24psi (when it died) took a long time. Asking too much from what is probably an emergency compressor.
 
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raggie33

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fuse is blowing becuase of high amps engine on or off should not make diifence
 

Lou Minescence

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I had this same problem on a Honda a few months ago. Blew the fuse for both lighter style outlets. Put a new fuse in and only one worked. Turned out to be the outlet that didn't work had a built in fuse. We unplugged the outlet and there was power going to it but that was it. We called the dealer for a new outlet and they told us about how it had a built in fuse that could only be serviced by replacement. So check for power at the back of the outlet. This could be your problem.
 

markr6

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A little different from the Grand Cherokee but close. In mine, the F90/F91 are user selectible. If you want it to provide power all the time, you simply move it over (up) a slot. Maybe it doesn't also protect the 120 inverter, but I don't have that anyway....so regardless, this fuse only does the 12v in back on mine. I'll have the replacement socket this weekend and give it a try.
 

orbital

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Keeping your car engine running is the best plan.

The voltage is staying up; so there is not an extra amp demand to produce watts.
also things/tools get less efficient when they get hot, so possibly even more demand on amps.... keep that engine running.

Hopefully it's just a cooked socket
 

bykfixer

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Not only everything you said there Orbital but lets just say your battery is a few years old and doesn't have all those cold cranking amps like new anymore, keeping the motor running while pumping up a tire ensures the battery wasn't run down to a point where yeah your tire is full but now your car won't start. Doh!
 

turbodog

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Keeping your car engine running is the best plan.

The voltage is staying up; so there is not an extra amp demand to produce watts.
also things/tools get less efficient when they get hot, so possibly even more demand on amps.... keep that engine running.

Hopefully it's just a cooked socket

Gonna have to disagree with this... as far as volts/amps/watts go. Running the engine will increase circuit voltage which will increase amps. We are not talking induction a/c motors here... permanent magnet d/c motors.
 

bykfixer

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Running an air compressor from just my battery causes my inside lights to dim. Running air compressor with the motor running does not.
I'll side with steady current over sagging anytime. Plus I know it isn't deep cycling the battery.
 
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