Cleaning copper oxidation from connector pins on a plug?

Discussion in 'General Electronics Chat' started by GRNDPNDR, Sep 9, 2018.

  1. GRNDPNDR

    Thread Starter Well-Known Member

    Mar 1, 2012
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    For the last week I've been tracing an electrical problem with my cars AC system. I finally found the problem and am looking for a little advice on doing a good and proper repair job.

    One of the main plugs in my fusebox has a bunch of corroded wiring right at the connectors. I went to the wreckers and picked up a spare to do the repair but even this plug has some corroded wires and I'd like to clean that up and if possible reinforce the connections. Possibly add a little touch of solder?

    As you can see in the image the good plug/wiring still has a bit of corrosion, and the pictured wire even already has a single broken strand from the corrosion.

    Any good ideas here to clean these up so I only have to do this job once and never again IMG_7561[1].JPG
     
  2. jpanhalt

    Expert

    Jan 18, 2008
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    A good crimp (e.g., one done at factory) should be airtight. Corrosion on outside does not affect conduction, and there is no reliable way to clean corrosion on the inside (doubtfully any there).

    That distribution of blackening seems odd, the entire contact was plated to begin with. Is it in a particularly bad environment?
     
    -live wire- likes this.
  3. GRNDPNDR

    Thread Starter Well-Known Member

    Mar 1, 2012
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    It's in the engine bay, connected to the main fuse box/integrated power module.

    The back of the plug is open to the air and elements, and man you should see the plug on the car itself. When I was inspecting everything to find the problem I grabbed the wire bunch that goes into that plug and a ton of copper dust fell out.

    In the picture above you can see a little bit of corrosion. I don't want to stick that back into the plug as it is and would like to clean up the wires slightly because I don't want them rotting out again and possibly leaving me with more than just an AC problem this time.

    In the picture below you can see the plug. it's open. as for corrosion on the inside, yes it's there. entire pins have rotted out of the plug on my car so I don't really understand where you're coming when you say it can't be cleaned and it shouldn't be corroded on the inside, because it is corroded on the inside and you can very plainly see that there is no airtight connection in the picture of the pin. The metal is exposed to the elements
    IMG_7562[1].JPG
     
  4. dl324

    AAC Fanatic!

    Mar 30, 2015
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  5. GRNDPNDR

    Thread Starter Well-Known Member

    Mar 1, 2012
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    Creepy. I literally just saw a video using this stuff. I might pick some up cause it seems like it might do the trick. I just wish I could find it locally because I pretty much have to fix this problem today.

    I'm going to poke around my local princess auto and see if they have anything similar. I'm only being so anal about it because I honestly don't ever want to have to do this again. one and done.
     
  6. dl324

    AAC Fanatic!

    Mar 30, 2015
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    I just read the MSDS info that came with my DeoxIT DP5 and it referenced something called ElectricALL that has a higher concentration of deoxidizer and was designed for automotive and marine applications. A local auto repair shop might have it.
     
  7. BR-549

    AAC Fanatic!

    Sep 22, 2013
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    If you want a one time job......order new connectors and wire pins. Trim cut all wires...install new pins.....shrink tube every connection.

    Shield area from future contamination.

    Spritz old connector and test with litmus paper.....is it acid or base?
     
  8. GRNDPNDR

    Thread Starter Well-Known Member

    Mar 1, 2012
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    Would you happen to know of any place that would sell these little specialty automotive pins? I'd love to just crimp another pin back on the wire and stick it back in plug. I doubt I would be able to get a plug assembly from a dealership. They may want to just sell me an entire harness for an insane price
     
  9. BR-549

    AAC Fanatic!

    Sep 22, 2013
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    I would search google. I would start off with year and model of auto and add "electrical connectors and pins"...to it and see what pops up.

    There are many online wire, cable, harness, and auto parts companies that will help on identity.

    Clean the best one off and get your caliper. An auto parts store might have a large index of connector/pins.

    An electrical supplier should have an index too.

    A car dealership will soak you for the connector. Perhaps a junk yard.

    Edit: the corrosion that I have come across......likes to crawl up the wire. Trim wire up to fresh insulation. And you will need the proper crimper. It will shorten the harness. It's a pain of a job.
     
    Last edited: Sep 9, 2018
  10. GRNDPNDR

    Thread Starter Well-Known Member

    Mar 1, 2012
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    Already been to the wreckers and grabbed a couple of extra plugs. I've pulled the pin and wire out that I need to do the repairs on and will just repin the entire plug with the rest of the wires because the plug on my car broke some pieces off, but the one I got from the wreckers is perfect.

    I've noticed the corrosion creeping up the wire, already pulled the insulation back cleaned it up and tinned the wire. I know that's not really ideal because it's likely more prone to breaking again in the future from vibrations, but the insulation was able to slide back up over the tinned wire to protect it.

    The extra plugs I grabbed had a couple that have already had this exact same thing repaired.....poorly, so I'm glad I managed to get a good plug in A- shape.

    This way the wire won't end up being shorter and I'll retain the factory wire colouring.
     
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  11. GRNDPNDR

    Thread Starter Well-Known Member

    Mar 1, 2012
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    circled pin on the bottom is the one that was completely corroded.
    all fixed up and looks like factory now. I took out all the pins on the old plug and replaced it with a newer looking one, cleaned up the wires and soldered on new pins.

    There was another pin that was nearly broken and it's fixed now too.

    curiously one of the extra plugs I got showed signs of a very bad and not working fix for this same AC plug by soldering a wire on to some kind of shorter pin and mashing it into the plug.
     
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