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Discussion Starter · #1 ·
I’m starting the arduous task of testing continuity on quite a few wires due to multiple codes that will not clear. I believe I have some wires that may be damaged. How can I safely test the female pins without opening them up to where it will create a loose pin fit? Are there special male test pins for meter leads that will fit properly without causing damage? I have the motor and transmission out and I’m re-covering the entire engine bay harness with high temp nylon loom and tesa tape and I want to fix any wire issues before putting the motor back in.
 

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Discussion Starter · #4 ·
Wow, no kidding! $120 is a lot of money, especially since I only need one. I'd like to figure out what size test pin I need for the PCM plugs. That's pretty much all I need. I might try the paper clip idea, but I'm concerned that it might stretch out the connectors and cause a loose pin fit issue. I do need something that will fit snug though so I can flex and wiggle the wires without the connector falling out.
 

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I have never probed the PCM connector on my Jeep, but have on other vehicles. Generally a small gauge wire or a few strands off a heavier gauge work fine. I have never worried about damaging the pins

What is it you're trying to figure out? Depending on what it is, sometimes measuring voltage where is terminates is the easier option.
 

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Discussion Starter · #6 · (Edited)
I have never probed the PCM connector on my Jeep, but have on other vehicles. Generally a small gauge wire or a few strands off a heavier gauge work fine. I have never worried about damaging the pins

What is it you're trying to figure out? Depending on what it is, sometimes measuring voltage where is terminates is the easier option.
Had some codes (very long story) and I found that if I zip tied the harness that runs against the transmission bell housing away, the codes did not come back. Fluke, maybe.

https://www.jeepforum.com/forum/f9/p0340-p0344-codes-driving-me-crazy-3965273/

But, I just want to check everything while I have the motor and trans out. So easy to work on the harness like this. I guess I could connect the battery and connect all the grounds to the body and check voltage then.
 

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Try just doing resistance values. Most meters have sharp pointed probes you can wedge in the back side of a connector to touch the metal contacts. Do this from one end of the wire to the other end.



Wiggle the wires around that are part of the harness you feel is the problem one. The values should not change when moving them. If you start seeing the values jumping all over the place that is a problem wire AND OR your probe is not getthing good contact.



Rarely do connections wear out as they are normally connected with no movement to cause wear. Corrosion will build up on the pins and cause all kinds of issues. I had a issue with a no start where I traced it back to the main harness that goes to the ECM. The pins looked fine but at the base one of them had that blue death on it. Copper corrodes blue when exposed to a acid. And if you ever have to take that connector apart you will realize those pins are not held in firmly but freely when you open it up. ALl those tpins will flop about in there and you got to figure out which goes were then. Its not super hard, but can be done. I got lucky and just cut the bad wire and pin out and replaced the pin. (I have all the tools to crimp tiny *** pins back to tiny *** wires. ai had to get my daughter to do that part as my hands are not as fine in the motor function.
 
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