Chrysler Repair: ASD blown fuse: 2.5 V-6, digital ohmmeter, amp fuse

Question
Roland followed your advise and here is our results:

pulled #1 oxygen fuse and that stopped short on ASD fuse; however, when reading continuity to ground still show on ASD fuse #5 and oxygen fuse #1

Also disconnected rear upstream oxygen sensor removed plenum disconnected distributor harness pulled ASD relay disconnected injector harness and still blow fuse when plugging in forward plug on PCM.  Is PCM bad or is it O2 sensor related?  Are there 4 O2 sensors?  Any help greatly appreciated.

Answer
Hi Tony,
There is an upstream and a downsteam oxygen sensor, a total of two. Fuse #1 in the PDC only powers the downstream oxygen sensor. Fuse #5 powers fuse #1 and everything else, including the upstream oxygen sensor. (By the way I overlooked the generator field coil is also powered by fuse #5 so if those coils were shorted to ground that could cause #5 to fail). Can you tell me the pin numbers on the front PCM plug? The fact that the #5 fuse stopped blowing when you pulled fuse #1 makes me think the downstream oxygen sensor is shorted to ground or its wire is. What happens when you disconnect that sensor? Is everything then OK?
On fuse #5, it could blow due to the combination of all the items that draw upon it. You would need to have a digital ohmmeter to actually diffentiate between a frank short and a normal resistance of 1 or so ohms. That 20 amp fuse will only blow if the total resistance is less than 0.6 ohms or so. So when you say "continuity"
that doesn't mean much that is helpful. I doubt it is the powertrain controller, but rather the sum of all the items, and you really need to unplug them all, one at a time, and measure the resistance to ground of each of them to find the one(s) that are drawing the most significant current. Current= 12/resistance. The total has to be less the 20 amp or the fuse will blow. Virtually all the wires that draw on fuse #5 are dark green/orange, so find them and check the resistance to ground of each item that has that wire color. The total resistance of parallel circuit of all these items is the sum of all the resistances divided by the product of all the resistances.
Roland