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Thu Oct 10, 2013 12:10 pm

You will often read "clean your ground terminals" or "check for corroded terminals and clean them".......
But, I've yet to read much about cleaning them.

The extent of my electrical cleaning experience is...
1. Wire Brushing /sand papering surfaces and terminals until shiny.

2. Using Baking Soda mixed in water to clean battery terminals and hold down hardware.

3. A can of Electric Contact Cleaner on contact switches.

Now. I've got the 86 Vanagon with corrosion at many many points throughout the body.
Interestingly a lot of the green growth on the terminals is on the grounding points......Why? Why does the ground lug attract corrosion?

I've pulled my fuel injection harness out of the Van. I've got many terminals that look brand new, some slightly grey and some down right green and fuzzy!

Is there an acid bath that you recommend to clean all of the terminals?

You certainly are not going to get a wire brush in some of these tiny pin connections!

Suggestions please!
Thanks!

Some photos......

Dave

Thu Oct 10, 2013 12:55 pm

I use Wurth Contact Cleaner. You apply it and let it set for say 15 minutes. Some used terminals that you can move in and out of the connectors will help too. Then some compressed air to dry it all out.

Thu Oct 10, 2013 1:21 pm

rsxsr wrote: I use Wurth Contact Cleaner. You apply it and let it set for say 15 minutes. Some used terminals that you can move in and out of the connectors will help too. Then some compressed air to dry it all out.

Well, I have CRC contact cleaner which I just sprayed on one of those ugly green terminals......

NOTHING!!

I could have been spraying compressed water on it! :roll:

Dave

Thu Oct 10, 2013 1:30 pm

this may be far from proper, but you asked what we (I?) do.
I use Muratic acid from the concrete floor cleaning portion of the hardware store
I have LONNNNNG handle medical q-tips and then a quench liberally with a carb cleaner, followed up with a new top sealing coat of something to prevent the newly etched copper from flash corroding.. often a silicone wire grease or fluid film.

makes then shiney copper, but at risk of corroding faster & worse the 2nd time if not properly rinsed and sealed.

Thu Oct 10, 2013 1:31 pm

I usually mix up some "strong vinegar" i.e. a 10% acetic acid solution - using photographic chemicals and let it sit in that for several hours; soak a paper towel in it and tape to a body panel with plastic over it

then spray with CRC contact cleaner or similar (DeOxit is good)

some will use emery paper but that can remove too much good material

- replace things if needed such as gnd. straps & gnd. stars

for those captive contacts, there should be a little tab you can move to release them from the plastic block

Thu Oct 10, 2013 1:36 pm

While you can't dunk a component any terminal or wire you can clean with hot water and baking soda. Hot like very hot tea water. Just dunk it in and let it sit for a minute and pull it out clean. I love this technique especially for battery terminals. No bushing the crap around and getting it in you lungs, no messy sprays.

Thu Oct 10, 2013 2:16 pm

Over on the tdi club they all swear by deoxIT contact cleaner
http://store.caig.com/s.nl/sc.2/category.188/.f

if you can spend the time use the D100S version w/o the flushing solution but if u leave residue it will attack the terminal but it does a great chemical clean
http://store.caig.com/s.nl/it.A/id.1605/.f?sc=2&category=188

in hard to get use the d5 version with the flushing solution it wont leave a residue that will mess up the terminal
http://store.caig.com/s.nl/it.A/id.1602/.f?sc=2&category=188

Thu Oct 10, 2013 2:34 pm

randywebb wrote: I usually mix up some "strong vinegar" i.e. a 10% acetic acid solution - using photographic chemicals and let it sit in that for several hours; soak a paper towel in it and tape to a body panel with plastic over it

then spray with CRC contact cleaner or similar (DeOxit is good)

some will use emery paper but that can remove too much good material

- replace things if needed such as gnd. straps & gnd. stars

for those captive contacts, there should be a little tab you can move to release them from the plastic block
Good advice. A vinegar solution will clean corroded contacts extremely well, as will wire brushing or sanding, just realize that it will also strip plating and the terminals will be even more prone to oxidization once stripped of their plating. Use Dielectric grease. Replacing the terminals would be the best method. Your van appears to be quite corroded.

Thu Oct 10, 2013 2:50 pm

greebly wrote: randywebb wrote: I usually mix up some "strong vinegar" i.e. a 10% acetic acid solution - using photographic chemicals and let it sit in that for several hours; soak a paper towel in it and tape to a body panel with plastic over it

then spray with CRC contact cleaner or similar (DeOxit is good)

some will use emery paper but that can remove too much good material

- replace things if needed such as gnd. straps & gnd. stars

for those captive contacts, there should be a little tab you can move to release them from the plastic block
Good advice. A vinegar solution will clean corroded contacts extremely well, as will wire brushing or sanding, just realize that it will also strip plating and the terminals will be even more prone to oxidization once stripped of their plating. Use Dielectric grease. Replacing the terminals would be the best method. Your van appears to be quite corroded.

Well, it is........ Being in NJ not only I we have humidity, we also have salt air! Neither of which is an ideal situation!

It is curious though why the corrosion favors the grounds! I'm sure that there is a scientific explanation with positive and negative ions or some such similar stuff!

Dave

Thu Oct 10, 2013 3:29 pm

djkeev wrote: greebly wrote: randywebb wrote: I usually mix up some "strong vinegar" i.e. a 10% acetic acid solution - using photographic chemicals and let it sit in that for several hours; soak a paper towel in it and tape to a body panel with plastic over it

then spray with CRC contact cleaner or similar (DeOxit is good)

some will use emery paper but that can remove too much good material

- replace things if needed such as gnd. straps & gnd. stars

for those captive contacts, there should be a little tab you can move to release them from the plastic block
Good advice. A vinegar solution will clean corroded contacts extremely well, as will wire brushing or sanding, just realize that it will also strip plating and the terminals will be even more prone to oxidization once stripped of their plating. Use Dielectric grease. Replacing the terminals would be the best method. Your van appears to be quite corroded.

Well, it is........ Being in NJ not only I we have humidity, we also have salt air! Neither of which is an ideal situation!

It is curious though why the corrosion favors the grounds! I'm sure that there is a scientific explanation with positive and negative ions or some such similar stuff!

Dave

I would say that grounds are pretty exposed on a car and are often ignored when problems begin to occur. I learned a long time ago to just replace battery cables and tranny ground straps at the first sign of problems, it seems stupid to try and eke a few more miles out of a fairly cheap part.

Thu Oct 10, 2013 3:42 pm

But look at the photo of my rear heater blower terminals, ONLY the brown ground wire terminal is corroded....... WHY?

Dave

Thu Oct 10, 2013 3:54 pm

I could be Galvanic corrosion. This is common in boats where to dissimilar metals touch. http://en.wikipedia.org/wiki/Galvanic_corrosion
The copper of the connector and the steel of the van. Just a thought.

Thu Oct 10, 2013 7:43 pm

I use vinegar followed by DeOxit.

Sat Oct 12, 2013 4:35 pm

Disassembling license plate, rear side marker and taillights for some sandblasting and minor rust repairs.

Again.......... extreme corrosion!
I ended up cutting the terminals from the wires rather than risk breaking the light sockets!........I'll install new terminals......

Interesting, one tail light, no corrosion, the other...... Corrosion ONLY ON THE BROWN GROUND WIRE TERMINAL.
Why? Why the ground wire? There is no dissimilar metal contact here, brass to brass.???.......

Dave

Sat Oct 12, 2013 4:43 pm

An overnight soak in floor stripper will get the terminals shiny looking. It will not hurt the plastic either (test to be sure though). I have done this many times and with some old pennies and they look brand new afterward. When I say floor stripper I am talking about the kind used by professionals to take off the acrylic wax on wal-mart style floors. It's available at home depot or the like in the cleaning aisle in 1 gallon bottles.

Sat Oct 12, 2013 4:44 pm

The reason you are finding corrosion on the ground connections is due to the electrons that have just passed through the device being powered telling the electrons in the metal contact just how much fun the ride was. So the valence electrons of the metal join up and head on to the battery.

The metal contact loses electrons, oxidation, and thus corrosion is the result.

:)

Alistair

Sat Oct 12, 2013 4:50 pm

Floor Stripper?......hmmmmmmmmmmmmm
MSDS information...........
------------------------------

HAZARDOUS COMPONENTS:

INGREDIENT(S) CAS # WEIGHT %

MONOETHANOLAMINE 141-43-5 5 - 10%

SODIUM HYDROXIDE 1310-73-2 1 - 5%

HAZARDOUS COMPONENTS:

INGREDIENT(S) LD50 ORAL - LD50 DERMAL - LC50 INHALATION -
RAT (MG/KG) RABBIT RAT

MONOETHANOLAMINE 1720 1 ML/KG NOT AVAILABLE

SODIUM HYDROXIDE 140 1350 MG/KG NOT AVAILABLE

Sat Oct 12, 2013 5:14 pm

djkeev wrote:

Interesting, one tail light, no corrosion, the other...... Corrosion ONLY ON THE BROWN GROUND WIRE TERMINAL.
Why? Why the ground wire? There is no dissimilar metal contact here, brass to brass.???.......

Dave
There is no Ground system on an automobile, the chassis is a return path. The vehicle is isolated from ground effectively by the rubber tires. As badly corroded as your return system is it indicates something sacrificial is occurring with the chassis. Perhaps you can utilize a sacrificial zinc electrode to act as an anode tied directly to the ground terminal of your battery and alternator. It will deplete instead of your ground corroding.

Sat Oct 12, 2013 6:40 pm

djkeev wrote:
Interesting, one tail light, no corrosion, the other...... Corrosion ONLY ON THE BROWN GROUND WIRE TERMINAL.

There is enough difference in the reactivity of the metals in the pins and wire terminals to cause corrosion due to the current flow. Galvanic corrosion requires current flow, it can be self induced flow or can be applied by an exterior force such as your charging system.

I am just glad I chose years ago not to live in a part of the country that uses road salts. :wink:

Sun Oct 13, 2013 5:41 am

Wildthings wrote: djkeev wrote:
Interesting, one tail light, no corrosion, the other...... Corrosion ONLY ON THE BROWN GROUND WIRE TERMINAL.

There is enough difference in the reactivity of the metals in the pins and wire terminals to cause corrosion due to the current flow. Galvanic corrosion requires current flow, it can be self induced flow or can be applied by an exterior force such as your charging system.

I am just glad I chose years ago not to live in a part of the country that uses road salts. :wink:

Ok...... So preventative steps to take once I clean everything would be......???

I'm guessing generous application of dielectric grease?

Dave