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View Full Version : mini 30 amp fuse under hood keeps blowing



jmartinez1228
07-10-2009, 10:26 AM
Hi guys im new to these trucks so im lost right now. My truck keeps blowing the small 30 amp fuse under the hood. Heres what happens. This happened to me a few days ago and all i did was swap it. i was able to drive the truck for a few days and just this morning the same issue happened. I dont have the manual so i have no clue what this fuse runs. Once the fuse is blown the truck still turns over but no ignition. Put a new fuse in and i can drive about a 1/4 mile before it blows again. any ideas as to what this fuse is and where to start looking? it obviously seems like an electrical short or some part going bad. any help would be appreciated. thanks

Mudderoy
07-10-2009, 10:29 AM
Ok you have a 1996 XJ, what engine? What is the position of the fuse in the block, we can look it up. 30 amp sounds right, but I'd like to make sure that is what is supposed to be there.

jmartinez1228
07-10-2009, 10:32 AM
Ok you have a 1996 XJ, what engine? What is the position of the fuse in the block, we can look it up. 30 amp sounds right, but I'd like to make sure that is what is supposed to be there.

im gonna say its the 4.0 inline 6. The fuse block is on the passenger side behind the battery. its the tiny 30amp fuse. The wonderful fuse cover that jeep put in doesnt say what it exactly that fuse is for.

Mudderoy
07-10-2009, 11:17 AM
I'm still trying to find a diagram of the exterior fuse box.

jmartinez1228
07-10-2009, 11:53 AM
I'm still trying to find a diagram of the exterior fuse box.

alright thanks, if it helps any i just found out that exterior fuse box is called the primary distribution center

Mudderoy
07-10-2009, 12:19 PM
alright thanks, if it helps any i just found out that exterior fuse box is called the primary distribution center

I can always walk out to my jeep and get my owner's manual, but it's hot out there! :smiley-laughing021:

jmartinez1228
07-10-2009, 12:38 PM
I can always walk out to my jeep and get my owner's manual, but it's hot out there! :smiley-laughing021:


come ooooon help a buddy out.

Melissa
07-10-2009, 01:29 PM
Would my 93 be the same as the 96?
I have my exterior fuse box that says what everything is

Mudderoy
07-10-2009, 01:30 PM
http://xjtalk.com/images/special/jeep_pda.jpg

Which one is it? None of the small fuses are 30 amp.

jmartinez1228
07-10-2009, 02:14 PM
thats not anything close to what i have. i took pix of it so you can see. its the little neon fuse.
http://s195.photobucket.com/albums/z203/jmartinez1228/jeep/

Mudderoy
07-10-2009, 03:21 PM
thats not anything close to what i have. i took pix of it so you can see. its the little neon fuse.
http://s195.photobucket.com/albums/z203/jmartinez1228/jeep/

Why are you missing a large 30 amp fuse?

jmartinez1228
07-10-2009, 03:26 PM
Why are you missing a large 30 amp fuse?

no clue thats always been like that. ill try and put that one in. but the smaller 30amp fuse on the left side of this picture is the one that keeps blowing.
http://s195.photobucket.com/albums/z203/jmartinez1228/jeep/?action=view&current=IMG_3886.jpg

Mudderoy
07-10-2009, 03:30 PM
no clue thats always been like that. ill try and put that one in. but the smaller 30amp fuse on the left side of this picture is the one that keeps blowing.
http://s195.photobucket.com/albums/z203/jmartinez1228/jeep/?action=view&current=IMG_3886.jpg

I understand, but I have seen situation when a fuse is missing that another "unintended" electrical path will be taken. The cover says you should have a large 30 amp fuse, but nothing there, so that makes me wonder what "unintended" electrical path may be happening.

Let me see if I can find out what that fuse is for before you put it in.

I can check my 1998 after work.

jmartinez1228
07-10-2009, 03:34 PM
I understand, but I have seen situation when a fuse is missing that another "unintended" electrical path will be taken. The cover says you should have a large 30 amp fuse, but nothing there, so that makes me wonder what "unintended" electrical path may be happening.

Let me see if I can find out what that fuse is for before you put it in.

I can check my 1998 after work.

i get what your saying now. But ive had this truck for 6 months without that fuse and im assuming my boss had it like that also. im beginnning to think it might be the automatic shut down relay because if it were the fuel pump relay it would just cut fuel off to the car correct? thats not what is happening. does the fuel pump have any ties to the asd relay?

Mudderoy
07-10-2009, 03:39 PM
i get what your saying now. But ive had this truck for 6 months without that fuse and im assuming my boss had it like that also. im beginnning to think it might be the automatic shut down relay because if it were the fuel pump relay it would just cut fuel off to the car correct? thats not what is happening. does the fuel pump have any ties to the asd relay?

Maybe someone else can answer that, I don't know. It's probably something simple, but I have to figure out what the fuse that is blowing is for. Assumptions seem to get me into trouble more often that being a good short cut in trouble shooting (computer mainly), so try and take a logical approach and weed out the assumptions as much as possible. That's why I noticed the missing fuse.

I'm going to stop guessing at stuff. I'll get some real information and we can continue, of course someone else may jump in at any moment.

jmartinez1228
07-10-2009, 05:05 PM
i just realized i was missing a 40amp fuse also on the bottom row. i just picked up a new asd relay along with all the missing fuses. also found a blown 15amp fuse under the dash. cant tell what that fuse is for though but im thinking the cig lighter since it doesnt work.

firehawk
07-10-2009, 05:43 PM
According to my 2000 XJ FSM, that fuse is supposed to be a 20 amp fuse. It is shown to be "fused ignition switch output (ST-RUN)". If your '96 is the same as my '00 it sounds like you might have an ignition switch problem.

Question I have is, is the ignition switch getting warm/hot? If it is, DO NOT park it in a garage!! I had an '88 Ford Tempo that had a factory recall on a faulty ignition switch. I was told IF the switch was getting warm to not park in in a garage until I got the switch replaced since there had been some that had caught fire while just sitting overnight in the garage.:smiley-scared002:

I checked a little deeper into the #26 fuse. It shows it feeds a power amplifier for a 6 speaker sound system. Now I'M REALLY confused???:cool: Maybe it was called a fused ignition switch output since you HAVE to have the ignition on, or in accessery to run the sound system? Hell try unhooking your radio.:D

jmartinez1228
07-10-2009, 06:31 PM
i picked up a new asd relay, 40,30 and15 amp fuses. when i tried to drop in the 40 i realised there are no connectors at all for this nor for the 30 amp fuse????? nothing at all. i also swapped out the 15 amp fuse under the dash but that didnt fix the cig lighter or the rear wiper that wasnt working. sooooooooo im stumped, i have a truck that turns on but cant drive lol this is crazy. From reading some info on the asd on a 97 its controlled by the pcm which im assuming is the ecu? it says that it gets a signal from the pcm to power the fuel injectors. i turned the truck on and wiggled the injectors to see if there was a short and it stil runs. im just afraid to take it out on the road since my road is really busy.

At the end of the day im still not 100% sure what this 30amp fuse is for except for the asd. when i unplug it the same effect that i get from the blown fuse is the same effect i get from removing the relay. soooooooo bad relay?

Mudderoy
07-10-2009, 08:31 PM
http://i195.photobucket.com/albums/z203/jmartinez1228/jeep/IMG_3882.jpg

http://xjtalk.com/images/special/jeepfuseboxext.jpg

lol and my 1998 is different from yours!

jmartinez1228
07-10-2009, 08:45 PM
lol unreal

jmartinez1228
07-12-2009, 04:13 PM
anything guys?

Mudderoy
07-12-2009, 04:31 PM
anything guys?

I sent an e-mail to one of our members with a 1997 XJ. Maybe he's got a manual for his Jeep.

jmartinez1228
07-13-2009, 08:24 AM
I sent an e-mail to one of our members with a 1997 XJ. Maybe he's got a manual for his Jeep.

i think i downloaded the 97 manual and when i looked at the wiring it didnt seem to look the same for the 96.

Mudderoy
07-13-2009, 09:33 AM
i think i downloaded the 97 manual and when i looked at the wiring it didnt seem to look the same for the 96.

All this time I thought you had a 1997. Now it makes sense why my 98 looks different. Sorry for the confusion.

Mudderoy
07-13-2009, 03:24 PM
http://www.justanswer.com/questions/6xq7-96-jeep-cherokee-sport-keeps

He says it's the fuel pump fuse.

You need to get at least an owner's manual for your XJ. I can't find one online, for free. Ebay has one you can buy and download now.

jmartinez1228
07-13-2009, 06:29 PM
http://www.justanswer.com/questions/6xq7-96-jeep-cherokee-sport-keeps

He says it's the fuel pump fuse.

You need to get at least an owner's manual for your XJ. I can't find one online, for free. Ebay has one you can buy and download now.

cant see the images but i get what your saying. Heres the weird thing though, i can still hear the fuel pump turn on prior to trying to turn the car over.

Mudderoy
07-13-2009, 07:30 PM
cant see the images but i get what your saying. Heres the weird thing though, i can still hear the fuel pump turn on prior to trying to turn the car over.

Yeah the pictures don't display, and the tech didn't sound over confident that it was a fuel pump fuse.

You checked all the other fuses, right?

ol"blue
07-13-2009, 10:40 PM
Have you tried checking it yourself to see if it might have set any fault codes? http://go.jeep-xj.info/HowtoECUcodes.htm

jmartinez1228
07-14-2009, 07:52 AM
Have you tried checking it yourself to see if it might have set any fault codes? http://go.jeep-xj.info/HowtoECUcodes.htm

yea all the fuses checked out ok. The only error codes that came up was a P1389 if i remember correctly and when i looked that up it said no signal from asd relay which im assuming happened when i took the relay out to see what would happen.

jmartinez1228
07-30-2009, 06:55 PM
So i have a new issue that came up. I usually start the truck up a few times a week so the battery doesnt die but i forgot for about a week and of course it was dead. Anyways after starting it about 5-6 times and watching it just dying without being able to idle i started her up and held the gas at 2k rpms for about 10 minutes. I then noticed my gas gauge was all the way to the right past the fuel mark (i had a quater tank) and my rpms were moving anymore. soo any ideas what that might be caused from?

Mudderoy
07-30-2009, 07:33 PM
Weird. My instrument cluster will stop working occasionally, when it's really cold out, but they all go to zero.