Restoring Your CE - Fuse/Relay Block

[uBoat Commander]

My understanding is that 928s don't like moisture, and corrosion is a problem in the best kept cars.

Tackling my fuse/relay box was a chore, as the "u-Boat" had been in a flood in 1999, with no attempt at repair until 13 years later by me. Hooking up a battery proved that almost nothing electrical worked. A glimpse at the fusebox gave a good indication why;



Underneath the moldy carpets was the mess above.

I decided to completely remove & properly clean/restore the block. It is important to understand that the corrosion on all of the connections increase ohms, or resistance. Enough corrosion and you get complete resistance - no curent flow.

If connectors anywhere were steel, I would have thrown this away & started new. However, all connections are copper, so beneath all of this corrosion is good copper.

The plugs on the bottom are color coded, but don't count on that for later re-connection - mark each with perm marker the position they were in. Trust me, it save confusiopn & frustration later.

I removed all the plugs, disconnected 1 ground wire, and pulled it all free;



Obvious frontal corrosion for relay placement, look at the fuse block, which was a wreck;


I wanted to take out the relays (to see if I could salvage any) and they all simply crumbled. I made an order to Pelican for every fuse/relay there is in the car - just over $800 worth. I was left with this;



CLR (Calcium, Lime, Rust) is a household cleaning product used for dissolving stains, such as calcium, lime, and iron oxide deposits. Its ingredients include water, lactic acid, gluconic acid, lauramine oxide, and Propylene Glycol n-Butyl Ether. Mild acidics that remove the above corrosions without affecting the underlying copper wire. It is liquid, so your part can be dunked in the stuff. That's what we did;



The purpose of dunking is to hit every piece of copper, protected by sheathing or not. I soaked it overnight, and results were phenominal. Took it out of the bath, rinsed it all with water, got this;



Look at that clean copper!

I then soaked the whole thing again with a mixture of baking soda, overnight, and rinsied it off with water again. This removes any excess acid still lingering, and is an environment electronics seem to like.

Blew the whole thing dry overnight, and re-installed NEW fuses and NEW relays;

DON't Forget the connectors in the car!! I did the same acid/alkali bath on the connectors in the car;




Next, TAKE YOUR TIME and re-seat / straighten all of the copper connectors for the fuses. Install all the fuses / relays while block is on your bench - makes life easier in the long run. USE DIELECTRIC GREASE ON EVERY MATING SURFACE!!! I picked up a tube at LOWES that will last me forever for like $5

GROUNDS - All this is moot without good grounds. In original pic, you will lsee two bundles of grounds mounted to the firewall - remove all, sandpaper both sides and mounting surface (I also used CLR on it) then re-install.

Those plugs you marked - dielectric grease on all connections & plug them in. End result looked like this;



I'm a big fan of cleaning ANY electrical connection with CLR and re-connecting with dielectric grease - If done properly, it will last longer than the rest of the car.

Thank you for watching, and remember - "Don't Try This At Home"

[AirtekHVAC]

I had a similar ordeal, but many of the pins from my relays had bonded into the stay-kons on the panel....mine was not salvageable. I found one on eBay, like new, for 100$....wen to a salvage yard and took relays from every German car I could find...then bought a few from eBay....the most expensive was the headlight relay....good job.

[curtisr]

Tried to recommend this thread for the PelicanWiki but this doesn't seem to work...

Editor?

[milspam]

I like your idea of using CLR - never thought of this, but should work very well without potential damage of removing contacts. Keep up the good work.

[77tony]

Nice job. More here:

Ground Cleaning, 16V Euro

[antsmands]

Exceptional work!

[Fixer]

Great restoration!

[Alan in AZ]

Nice job on cleaning it really came back well - however note that dielectric grease is an insulator. It would not be my first choice to use like this as it does not promote electrical connection (quite the opposite in fact). The value it has here is to inhibit future corrosion - but its best for that for it to be only sealing the contact area not actually within it.

I think it would be better to gently mechanically clean the fuse caps and fuse holder mating surfaces, spray or wipe with a contact cleaner/promoter (DeOxit/Sabilant etc). install the fuses - then spray with a contact protector to seal out against future corrosion.

For the relay's pins & sockets I'd use the contact cleaner/promoter only - these contacts have large mating areas and aren't usually subject to the issues we see with the barrel fuses.

Alan