Cleaning corroded wiring terminals

Joined
Sep 30, 2005
Any one have suggestions on how to best clean corroded wiring terminals? Specifically, in the harness at the ECM and the ignition module?
 
Unless they are really corroded I'd use spray on contact cleaner other wise get new terminals from Caspers and be done with it. John
 
Replace the connectors with Casper's pigtail replacement connectors. It's a bit time consuming but worth it. I've done this on my ignition module and ECM connections. Cut, strip and solder then slide shrink tubing over, one wire at a time.
 
Soak the terminals in Coca-Cola or another acidic soft drink and then use a wire brush or even an old tooth brush. Careful with the wire to terminal connection and then protect that area. Good luck.
 
Heat shrink & seal butt connectors are much faster and easier than solder and heat shrink

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Once a terminal is corroded, you can't ever fix it. The tin plating on the terminal deteriorates, leaving the bare brass base metal, which tarnishes naturally. When brass contacts tin, it causes further corrosion via electrolysis, due to dissimilar metals.

There is only one fix; replace all terminals involved. And if the ECM connectors have terminals that are corroded, the ECM itself has taken a hit - you will be replacing that end as well.
 
But much less reliable.
Well since they are THE approved method of repair for air bag circuits per GM and the fact that Ive used thousands of them over the years with zero issues I would strongly dissagree with that statement. Everything from air bag circuits, ECM & other module replacement connectors, medical equipment repairs, etc. Not 1 failure. Im not talking about regular butt connectors. I'm talking about properly sized butt connectos that heat shrink and contain a sealant to make a weatherproof connection

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^ cool. I'll look into those. And yes, plan on swapping the ECM too. I'm chasing down a code 42 and stumble/)miss issue. This is my next step.
 
Once a terminal is corroded, you can't ever fix it. The tin plating on the terminal deteriorates, leaving the bare brass base metal, which tarnishes naturally. When brass contacts tin, it causes further corrosion via electrolysis, due to dissimilar metals.

There is only one fix; replace all terminals involved. And if the ECM connectors have terminals that are corroded, the ECM itself has taken a hit - you will be replacing that end as well.

+1
 
No question the sealed splice sleeves work nicely. As long as you use the approved crimp tool, you'll have a perfect connection.

The only problem with using barrel splices is that the 48 splices required to patch in the ECM connectors turn into a big ball of splices, with no place to put them. The kick panel is tight to start out with, and added splice sleeves turn into a clearance problem. You can stagger them, but they still take up too much space.

This is why it's desirable to solder the wires individually, then slip thin-wall heat shrink over each soldered connection. They will pack tightly into the kick panel area without an issue.

We build harnesses for GM and they don't allow crimped splices; only ultrasonically bonded splices will meet the spec. We have a special ultrasonic welder that is required for OEM applications. This welder actually forms a solid copper block where the wires join, and you can bend and wiggle the joints and they won't come apart or break.

Bending and wiggling solder connections can cause stress where the solder stops, which could cause cause breakage of the connection. So once you solder, don't move it.
 
Would it be better to just de-pin the connectors, cut off the terminals and crimp new terminals on and then push them back into the original connector? I don't see the terminals by themselves on Casper's website. Are they available? Would need the correct de-pin tool too.

Or is it preferred to just splice the pigtail connector?
 
Would it be better to just de-pin the connectors, cut off the terminals and crimp new terminals on and then push them back into the original connector? I don't see the terminals by themselves on Casper's website. Are they available? Would need the correct de-pin tool too.

Or is it preferred to just splice the pigtail connector?

The female contacts are a bit tricky to remove without damaging the plastic connector. Crimping on new terminals will require the proper tool $$, as well. A soldered connection is very reliable and in most cases superior to crimp in the long term.
 
There are tools available for removing the pin's but the removal can often damage the pin (I was copier tech so I'm guilty of trashing pin's).
 
Actually those pins slip right out if you use a terminal pick and put it in the right place. I sometimes (actually all the time) use a $2 sewing seam ripper to remove the pins, and can de-pin a 56 cavity connector in less than 3 minutes. Remove the TPA comb and it's very simple.
seam-ripper.jpg


That said, the terminal replacement is a bit more complicated. The crimp design needs to be unusually flat at the wire gripping area in order for the terminal to slip into the connector unrestricted. It's actually a specific hand tool that is used for crimping those special 100-series female terminals.
 
Anybody know what gauge size wire is at the ECM connectors? I'm thinking I'll do the splice butt connectors suggested in this thread, but want to make sure I get the right size splice connector.
 
We use shrink tubing w/ adhesive in it....Doesn't slip, grips the wire, helps keep moisture out.
 
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