IOD Fuse keeps blowing
#1
Thread Starter
Junior Member
Joined: Oct 2014
Posts: 50
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From: Northwest CT
Year: 1998
Model: Cherokee
Engine: 4.0
IOD Fuse keeps blowing
Went to go for a drive this morning. I have a broken vacuum line that was patched with electrical tape that I wanted to make sure wasn't leaking so I popped the hood and checked it, all looked fine so I shut the hood and hopped back in. All of the gauges and radio were no longer working.... I shut the engine down and opened the hood to check if I hit something inadvertently while checking that vacuum line. I didn't see anything and got back in and tried to start it. It started very hard but once running, it ran fine. Once warm, it started up normally. I checked all of the fuses that applied to the offending issues and found that the #16 fuse under the hood, the IOD fuse, was blown. I then replaced the fuse and it blew after about 15 seconds. I pulled the radio first as I had just changed it (still a stock radio) and it blew a 10A fuse immediately. I then put a spare 20A fuse in and the gauges all came back and worked correctly but there was a strong electrical burning smell so I pulled the fuse and it was extremely hot. I pulled the instrument cluster and put in a 15A fuse, it blew immediately. Changing up to a 20A made no difference, blew immediately as well. I can't see any evidence of mouse damage or burned wires but the problem doesn't seem to be getting any better... I'm confused and annoyed. Please Help
#2
Never stick a higher amp fuse where a lower should be. Even for testing. Atleast i dont. Wiring can overheat using a larger amp fuse as the load increases (more heat). That burning smell was most likely insulation. You can create a short doing that and ruin your harness, or even start a fire. Do you have a testlight?
What year is it? The IOD fuse for my 97 is #17 in the PDC, and #16 is the power amp fuse. According to the owners manual.
What year is it? The IOD fuse for my 97 is #17 in the PDC, and #16 is the power amp fuse. According to the owners manual.
Last edited by fb97xj1; 01-14-2017 at 01:30 PM.
#3
CF Veteran
Joined: Aug 2010
Posts: 8,357
Likes: 90
From: Canton, MI
Year: 1999
Model: Cherokee
Engine: 4.0
The owner's manual can be wrong.
Here's the PDC fuses. 97 should be close to the same, if not identical.
The OP is dealing with the correct fuse for the IOD.
The IOD should be identified on the lid for the PDC.
OP,
Pull the 50 Amp JB fuse and see if the IOD fuse still blows. This fuse feeds the JB which has many fuses/circuits associated with the IOD circuit.
.
Here's the PDC fuses. 97 should be close to the same, if not identical.
The OP is dealing with the correct fuse for the IOD.
The IOD should be identified on the lid for the PDC.
OP,
Pull the 50 Amp JB fuse and see if the IOD fuse still blows. This fuse feeds the JB which has many fuses/circuits associated with the IOD circuit.
.
#4
CF Veteran
Joined: May 2012
Posts: 7,964
Likes: 958
From: Lost in the wilds of Virginia
Year: 1998 Classic (I'll get it running soon....) and 02 Grand
Model: Cherokee (XJ)
Engine: 4.0
Please allow me to slightly rephrase the esteemed forum member's comment:
NEVER NEVER NEVER NEVER NEVER stick a higher amp fuse where a lower should be. NO! NOT EVEN FOR TESTING! NOT EVEN FOR A FEW SECONDS!!!!
So now you get to figure out what damage you did... who knows where.....
#7
Thread Starter
Junior Member
Joined: Oct 2014
Posts: 50
Likes: 0
From: Northwest CT
Year: 1998
Model: Cherokee
Engine: 4.0
I thought I had the problem solved, hitting the brakes sometimes caused the dash lights to come on as if the headlights were turned on. After changing the headlight switch everything went back to normal and the fuse didn't blow. However, yesterday sometime after changing the oil, the IOD fuse blew again while the Jeep was sitting in the driveway turned off.... Pulled the 50A JB fuse, replaced the IOD fuse and everything seemed to work fine. It would seem that there is no short in the interior lights or gauges. However, the problem seems to have magically fixed itself again so I can't troubleshoot anymore atm
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#8
Thread Starter
Junior Member
Joined: Oct 2014
Posts: 50
Likes: 0
From: Northwest CT
Year: 1998
Model: Cherokee
Engine: 4.0
Figured it out. Just got home, opened the door and the interior lights were super dim. After about 2 seconds, they came back and I started to see smoke. Tried to find the source and began to hear crackling. Turns out there was a short in the connector feeding the cargo light and rear speakers(not sure if thats actually the connector but it's all covered in powder now). Now to fix that and the rusted out rear quarter that probably caused that in the first place.
#9
CF Veteran
Joined: May 2012
Posts: 7,964
Likes: 958
From: Lost in the wilds of Virginia
Year: 1998 Classic (I'll get it running soon....) and 02 Grand
Model: Cherokee (XJ)
Engine: 4.0
Hmm. So, you found a smoking gun, did you?
That's a relief! Now you know what to fix.
That's a relief! Now you know what to fix.
#11
Thread Starter
Junior Member
Joined: Oct 2014
Posts: 50
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From: Northwest CT
Year: 1998
Model: Cherokee
Engine: 4.0
So, on the left is the connector I thought was on fire last night. On the right is the connector that was actually on fire that I couldn't see... quite a bit worse than I had originally thought
#13
Thread Starter
Junior Member
Joined: Oct 2014
Posts: 50
Likes: 0
From: Northwest CT
Year: 1998
Model: Cherokee
Engine: 4.0
Were your rear quarters rotted out? Mine were and I'm pretty sure the connector got corroded and packed with mud and started drawing way too much current.
I still need to get a new connector... I just soldered the wires together and covered them with heat shrink with every intent to fix it right.
That was a year and a half ago almost
I still need to get a new connector... I just soldered the wires together and covered them with heat shrink with every intent to fix it right.
That was a year and a half ago almost