View original topic: Cleaning ground trees: how to?
jimf909 Sun Jul 12, 2020 11:11 am

I know there are plenty of "cleaning grounds threads" but I haven't seen this answered...

Cleaning ground trees...

Does polishing/removing the coating (zinc?) on the ground trees increase the likelihood of corrosion?

My dad used to say that the coatings on oem electrical contacts provided corrosion resistance and to not polish it off (tough to do when it's corroded). Does polishing like this increase the likliehood that it will corrode? Does adding a smear of Dielectric grease return corrosion resistance?

Alternatively, what's a good method for cleaning oem contacts?

- Polish (if corroded)
- Deoxit contact cleaner ?
- Reassemble
- Smear with dielectric grease?

Wildthings Sun Jul 12, 2020 11:30 am

A wire brush, a small piece of emery cloth that you can bend over the tab and twist around the remove the corrosion. I typically just use dielectric grease to keep further corrosion in check, but a NO OX grease would be fine.

I don't live in an area where corrosion is rampant, so what I often do is remove the female spade, put some dielectric grease on the male and slide the female on and off several times, figuring the sliding action provides me with a sufficiently cleaned male spade. Of course if the female terminal is a loose fit, replacement or at least careful pinching of the female terminal may be required.

sphet Sun Jul 12, 2020 11:45 am

My dumb question is can you do this without removing the dashboard?

jimf909 Sun Jul 12, 2020 11:59 am

Yes, those two came off while the dashboard was in place. I do remove the driver's seat for this type of work (reaching under the dash). It takes a minute or so to R&R.

Remove driver's seat > unscrew and drop the fuse box > contort yourself, get acquainted with the ground trees and wires > remove connectors and clean. Grab a stubby phillips if you want to actially remove the ground trees.

Here they are above the fuse box on the driver's side of the dash. There are 15-20 grounds on the van described in the Bentley or a pretty good thread here.

ALIKA T3 Sun Jul 12, 2020 6:19 pm

Definitely protect these ground tree now you cleaned them, their yellow zinc coating is gone.

Oftentimes the corrosion on these trees is due to a leaky rusty windshield bay.
The crimp connectors also corrode and become brittle, one side of the curl cracked and about to fall out causing bad connection. When you pull the wire, or when you put it back will reveal such issue. Some of them will crack when you try to tighten them a but too. Things to pay attention to :wink:

Abscate Sun Jul 12, 2020 7:26 pm

Dremel tool

jimf909 Sun Jul 12, 2020 9:18 pm

^^^ Agreed. The Dremel is in the photo above. The wire brush was there just for show. :D

alaskadan Mon Jul 13, 2020 6:01 am

I bought one of those scratch pens with the refillable fiberglass inserts. Read about it here. It kicks ass for those kind of things. Was like 19 bucks with an extra package of refills. No more folding a piece of sand paper over a whatever to reach those little spots. As the bristles wear they are always new and sharp, it's like a 120 grit sanding tip that's always new.

jimf909 Mon Jul 13, 2020 7:45 am

^^^I had no idea such a thing existed. It looks useful.;sr=1-6

Glenn Mon Jul 13, 2020 8:05 am

Might want to consider a chemical cleaner since oxidation is a chemical process and reversing it is a better way.

Using abrasives is a sure way for the oxidation to quickly return and is a short term solution.

Just saying....

jimf909 Mon Jul 13, 2020 10:42 am

^^^ I've been using Deoxit to remove oxidation. Are there any favorites out there?

Mark Lewalski Mon Jul 13, 2020 12:21 pm

Maybe just replace them for a few dollars?


plummerdesign Tue Jul 14, 2020 10:24 pm

ALIKA T3 is right.
Those female connectors are ANCIENT. They are brittle too.
Make a day of under dash fun!
Get new ground trees AND a bag of German female connectors. They take a different crimping tool, one you will wonder how life was doable without. I use an IWISS #IWS-1424B to crimp these and any other OEM crimp (fuel injector connectors, temp II connectors and so on).
I know, its a bad party. But great grounds get the good party started!
: D

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