So after completing a job replacing my blown T-Case, the Disco is dead. The engine does nothing when I turn the key. I've never experienced anything like this, and the truck has only been sitting about 2 months..

When I turn the key to the on position, the F2 Engine Mangement System fuse pops... I have read through tons of threads and I went through the process of unplugging everything that this fuse is used for. O2 Sensors, MAF, SAI pump, the plugs on back of engine.. etc... and nothing changed.

BUT! I found a thread that said to check if the F2 fuse will blow with the F13 BCU fuse unplugged. Well, the fuse does not blow when the F13 fuse is not in it's slot... but, the engine still does absolutely nothing when I turn the key..

Am I looking at a messed up BCU? I did nothing to it during this process.

What I did notice, is when I took off the exhaust manifolds to fix busted flange bolts, is that the engine ground strap from the driver side firewall to the engine is ripped in 2... I am going to fix that tomorrow, but I still don't think an engine ground would cause this.. Am I wrong??

 

Short to ground, before the load will always blow the fuse.

Check the harness where you were working. make sure nothing is pinched.

 

How do I test? Is there a plug under the fuse panel?? Do I test from the top or do I test from the other ends of the harness?
I have Fluke10 multimeter which I'm good with.
I assume it's the F13 harness that is shorted?

 

Should there be a harness pig tail at the fuse box where I can test each post to find the faulty wire?? Then trace that wire to the problem??

 

I've been under the rig for an hour with a flashlight and don't see anything.. All wires look free from chaffing and pinches..

I'm going to take the center console back out and look around from the top...

 

Fuse #13 also coincides with the inertia switch. But, if you are blowing fuse...yes...you have a direct short to ground. Check all harnesses involved. Wish you would have just piggy-backed this information into your other topic.

Edit: Since you replaced the transfer case...I'd look in that area especially.

Good luck.

Brian.

 

Sorry for the late response.

On top of the transfer case, there should be 2 or 3 harness bundles. I don't remember what they controlled, but some were transfer-case and Transmission. Also, you may want to check the harness under the center console. I had an issue with another member where he did a CDL level and after re-assembly, had flashing lights. Turns out, one of the screws that holds the center console down, nicked the harness creating a short to ground.

 

So during the phase of changing out my Transfer Case, the Disco sat on ramps for a few months. It didn't occur to me that this might cause unusual water run-off. But I recently saw some say that these trucks can leak through the wind shield onto the computer behind the glove box.

So a few days ago I was looking for something in the truck and found a puddle of water in the passenger floorboard. We had some heavy rains a few days prior to me spotting the water. So I assume thats my culprit to the blowing fuses.

Is there a thread to how to go about replacing the computer? Also, would it be sketchy to find a computer that is closer to the miles on my engine and not the miles on the truck itself?

Any Ideas welcome!!

 

So I have taken all the plugs off of the ECM and BCU boxes behind the glove box and blew them out with compressor. I did not see any moisture or any signs of moisture underneath the dash..

I tested all O2 sensor wires and found no resistance from them. still popping fuses though

 

So the ECM plug CO635 is the one blowing the fuse... I tracked it down with process of elimination.. I am having dificulty tracking down what it goes to..

Can anyone point me in the right direction?? I think it is for the O2 sensors, but not positive