Easy question
 

How to you clean the copper connections? Metal brush?

For electrical connections?
If they are green with corrosion use a bit of vinegar on a brush to remove then rinse with water. Then some fine Emory cloth or sandpaper to polish.
A fine stainless brush will work as well. Make sure the battery is disconnected.

If you use an acid I would neutralize it...
Bigger thing for long life is to use some dielectric grease to seal and protect the connection.

As to the original question: Clean what copper? More detail gives better answers.

+1 on dielectric grease.

Connections aren't exactly of the weather pack style (used on all makes today) on these old birds.

Yes, as others have suggested, dielectric grease in a light film applied after cleaning is a good thing.
(Assuming we are talking electrical connections) ...... :)

Yeah, copper electrical connections such as for the fuses or the tab connections for electrical wiring.

So vinegar, stainless steel brush and then some dielectric grease. Sounds good! Thanks!

Hi Ace,

I used a brass wire wheel on my Dremel and that did the trick very well. I pulled all the fuses and did the box connections and the fuses themselves. Don't forget the couple-three in the engine compartment...

Franny

Interesting. I have a dremmel, but not the brass wire wheel. I bet it cleans up nicely. Home depot for the wire wheel? How about HF?

Or just about any hobby store... I bet HF has them too. I think I got a big assortment at Costco some years back and I'm due for another. I used the brass wheel so as not to be too rough on the contacts and not add a completely dissimilar metal.

There are sooo many connection points on the car with lots of grounds. I pull them and clean them as I find them. I'm not a fan of electrical issues ;)

Franny

I looked for the brass wheel at HD and couldn't find it. I ended up with a "Finishing Abrasive Buff". It looks like it will work well on the fuses. I got an Volt meter as well. I think I over bought on that one. It does a bunch of stuff ~$50.

By far these are the absolute best things for cleaning electrical connections for any kind of car. I've been using them on my motorcycles for a long time and recently ordered some more refills. Be careful that the little bits of fiberglass don't get in your fingers as they can cause problems.

Fiberglass Pen

I disagree on the dielectric grease. this grease is a barrier to electrical transmission, look it up on wikipedia. Use some wd40 or other corrosion protection lubricants.
I used dielectric on some bulb contacts and could never get a good connection.

also rotate the fuses while hosing them down with DeOxIt every so often

dielectric grease will be squeezed out from the contact areas; you use a very thin film - for more, search on those two terms and carefully read the comments from the late Jim Sims, an expert on such issues (according to the DOE)