Chrysler Repair: ASD fuse repair


Question
QUESTION: Roland I found the real #46 pin but was on the front plug of the PCM closest to radiator it wouldn't even register on the multimeter for resistance.Also after closer inspection with the help of my wifes good eyesight the pins on my ASD relay plug the numbers are 82,87,83,70,79 and on the starter relay they are 97,91,92(center terminal)89,93.Thanks again for being so patient and helpful

ANSWER: Hi Steve,
So we now know that there is no short circuit in the wires themselves. As to the numbers on the relay sockets, those don't exactly agree with the manual numbers so the best thing for us to do is to describe the pins as front, rear, inboard, and outboard (the central pin is not used.
The residual question I have is that before you removed the correct PCM plug you said that the resistance reading from the fuse socket was 1.5-0.08 ohms. Was that due perhaps to the meter not being solidly connected and if so, did the reading seem to be more like 1.5 or 0.08.  As I explained, the 0.08 would cause the fuse to blow, the 1.5 would not blow the fuse though it is still surprisingly low to be due to the PCM being itself.  A reading of 0.6 will indeed blow a 20 amp fuse.
Let us assume that 1.5 is the PCM plug 1 "draw" and is proper and let us then start putting things back in place while measuring the resistance to ground from the fuse pin #53:
Put both the PCM plugs back in and verify that you have 1.5 ohm, and tell me that result. Then remove both PCM plugs and tell me that result.
In the following steps by "tell me the reading" I mean if the reading drops below 1.5 ohms then stop and send me a follow-up question telling me at what point the reading dropped below 1.5 ohms:
Put the ASD relay in and tell me the reading
Remove the relay, then jump a wire between the rear and front pin sockets of the ASD relay socket, and tell me the reading.
Then put fuse 1 back in and tell me the reading.
Put in the generator plug and tell me the reading.
Put in the distributor plug and tell me the reading
Put in the Upstream oxygen sensor plug and tell me the reading
Put in the put in the egr solenoid plug and tell me the reading
Put in the fuel injectors one at a time and watch and tell me the reading.
There is no need to do further rating/nomination. Please only use follow-up questioning until you no longer are allowed to ask a follow-up, then start a new question.
Roland





---------- FOLLOW-UP ----------

QUESTION: I put both PCM plugs back on the resistance at fuse #5 was a0.10-00.9.With both plugs out it wouldn't register at all.I put the ASD fuse back in the socket and a resistance reading of 01.0-009 again.I'll start  the (tell me the reading)Might take a few but if it was reading 1.5(I'm not certain I had a good connection with the 1.5 reading cause these measurements were pretty stable on the movement of the meter this time)Should I be looking for  below 01.0-00.9?

Answer
Hi Steve,
Thanks for the report which changes my view of the situation.
By the way, I don't want you to put the ASD fuse #5 back in yet. I would expect that fuse to blow, based on you measured 0.1 ohm showing on pin 53. Every measurement should be with that fuse removed.
Here is what changes my view of things. If it is the case that with fuse 5 socket empty (no fuse) and the ASD relay removed and no jumper installed in its socket yet, when you had both the PCM plugs in their sockets you have a reading of about 0.1 ohm and when you had the PCM plugs removed you had no reading (which means more than 200 ohms) then it appears to me that there is a short occurring inside the PCM OR in an item that are using voltages created by the PCM. Any reading of under 0.6 ohm is enough to blow fuse 5 so we have to get that reading raised way above 0.6 ohms to solve the problem.
So put both PCM plugs in, verify the very low reading (0.1 ohm) to be the case a pin 53, and then:
Turn the ignition key to run, and go to the manifold absolute pressure sensor and verify that there is 5 volts compared to ground on pin 2 (violet/white wire) and if so, then put that plug back in and then go to the crankshaft position sensor plug pin 1 OR to the pin 2 of the 6-pin plug at the distributor (orange wire in either case, which ever is easier to get to) and verify that there is 8v on that wire.
Let me know the results of these tests.
Roland