Topic: Fuse #12 under dash blowing

[aka-justin]

The #12 PDC RELAYS SKIM (10A) fuse continues to blow, rendering my Jeep a rolling paper weight. It left me stranded on the way home tonight and had to have it towed.

I blew 4-5 fuses trying to isolate the source of the problem on the side of the road. I tried disconnecting all the relays, computer, and still nothing. According to the FSM, the only thing #12 powers is the SKIM (Sentry Key Immobilizer Module), Fuel Pump Relay (PDC), ASD Relay (PDC), and the Power Control Module. I even resorted to 15A fuses since I had ran out of 10A. I disconnected everything except the SKIM. The SKIM Module is next to disconnect before I try a fuse again (I'm out and need to buy more.) There's also some harness connections under the driver side dash that can be disconnected which I plan on trying. Pin-pointing this problem is not fun and it was getting late tonight with time against me, so I threw in the towel for the night and I'll just have to car pool tomorrow.

I'm annoyed to say the least.

Just as an FYI - the symptoms are loss of gauges and no movement (even with a cycle of the key in the ignition from off to on); engine cranks but will not fire up; check engine light on; fuel light on; blown fuse in #12 under the dash; no communication from the ODBII port to a scan tool).

[aka-justin]

[sharpxmen]

disconnect the SKIM and see if it blows again, if it does then you have a short in the harness (just stating the obvious i guess, i'm sure you figured that out already). Problem is that i think it won't run without the SKIM plugged in.

[aka-justin]

disconnect the SKIM and see if it blows again, if it does then you have a short in the harness (just stating the obvious i guess, i'm sure you figured that out already). Problem is that i think it won't run without the SKIM plugged in.

Spot on what I was figuring - thanks. I'll let you know how it progresses. For now, sleep.

[aka-justin]

Sorry no pic update, but I fixed the issue. I disconnected the SKIM module and it still was shorting. This time - I don't know why I didn't think of it earlier - I used a light bulb instead of a fuse. I wiggled the bundle of wires around that run from the fuses under the dash and over, no dice. I wiggled the bundle going over the firewall and the bulb started to flicker - getting warmer. I started pinching the bundle until I got about over the valve cover right were the hood light is connected and bingo, found the short. I took it all apart and I couldn't see any obvious breaks in the line where it was shorting...  So, f#$@#$% it... I opened the entire harness from along the firewall over to the PDC and computer and re-placed the entire line.  The short is now gone and I'm back on the road. Talk about a PITA! I found hack/splices by the PDC where it looks like cables may have been cut at one put on accident during the fender install, but I don't care. The circuit in question is replaced with new 18ga wire, soldered, and heat shrink-ed. I also got some cloth wrap and re-wrapped the entire harness. I attacked it after work today only becuase I was so angry that I was called in last night and had no vehicle to drive. I'm calmer now that it's driving and I had a few beers ... just in case.

[sharpxmen]

cool, glad you fixed it

[aka-justin]

cool, glad you fixed it

Thanks, me too. Here's what the loom likes now. I was to tired and mad to mess with pics when I was working on it earlier.