Wednesday, May 9, 2012

Re-Fusing The Box

With the rear of the car assembled, I was itching to try out my new tail lights but unfortunately, they required a power source of some kind.  I decided that even without an engine, a certain amount of fun could be had with an electrical system... if I had one.

So, I set out to bring Ol' Rusty to life by giving her an electrical system.  I had decided long ago to reuse the existing harness because it looked okay to me.  I dug it off the shelf and set to cleaning it up and upon inspecting the fuse box saw... rust?  Rust?  In a fuse box?  Can't I get ONE friggen part of this car that doesn't have rust!?  Oh well, I did a search for clips and found that new sets of fuse box clips are sold by most of the Mustang parts dealers.  They cost around $30 a set though which is pretty pricey for a set of 10 small metal clips.  You'd think they'd be like $1 each or so?  I searched the various electronics dealers (Digikey, Newark, etc) and couldn't locate any clips that were exactly like the originals.  VMF user, MidLife, quoted some part numbers in various VMF threads but the parts that came up under those numbers didn't look right to me so I just went ahead and paid the big bucks for my clips.  Also, there is an "Instructable" on doing this task (but in a Falcon) which served as my motivation.  Lastly, the guy who did the Instrucable told me that the contacts he uses are purchased via eBay for about $10 a set.  Unfortunately, this was after I had already purchased the more expensive clips.  Search eBay for "64-67 Ford Falcon Mustang Fuse Box Repair Kit".

When I received the clips, I compared them to the originals and found that although they were a dimensional match, they were considerably heavier gauge metal than the originals.  You'd think this would be a good thing but it presented some issues, not the least of which was the great difficulty in crimping the wires into the tails.  The small tabs would actually snap off before they would bend over.  Possibly, this could be avoided by heating the clips first but it really turned into a pain for me quickly.  I finally decided to just solder everything. 

I took a lot of reference pictures of where the individual wires were routed within the confines of the box.  Some snaked between others to make room for its crimp tail and some of the crimps were bent at strategic angles to clear wires and other clips.  All of which had to be considered in attaching the new clips.  Another issue that had to be dealt with is the shortening of the wires by approximately 1/4" per clip (required to remove the old clip and allow room to solder in the new one).  This required the main harness cable to have it's insulation removed back about an inch from the box to allow the wires within to be brought further into the fuse box to allow for this additional 1/4".

The old clips were removed by reaching a small screwdriver in on each side of each clip and working the clips locking tabs back against the clips and away from the fuse box plastic tabs.  The clips could then be worked out the back of the fuse box.

After I had completed the soldering and cleaning up the fuse box, I inserted the clips back into the box from the clips closest to the harness to the bottom end of the box.  The clips were all inserted up to their locking tabs and then I used a small hammer and punch to drive them in all the way and lock them down. Keep in mind that since these new clips are such a heavy gauge, I think it's highly unlikely that these tabs could be pressed enough to get them out of the fuse box ever again so make sure your work is good enough to be permanent.

After completing the fuse box rebuild, I finished cleaning up the wiring harness and the connectors.  The male contacts were cleaned with a brass wire brush and the female contacts were cleaned using a .22 caliber (think guns) wire barrel brush that I sacrificed for the task although I had to clip off 1/8" of the end of it (a wire loop).  Also, here's a VMF thread on cleaning harness contacts.

An now, onto the process:

When I started I noticed something wrong with the left-most contact on the bottom fuse.

The back side.  Yet more rust.

The damage could be better seen with the fuses removed.  I'm starting to remove the clips here by pushing a screw driver down next to the flat blade of each side of the clips.

After the tabs were suitably depressed, the clips could be pushed out.

... and removed.

Quite the rusty clip there.  Imagine the electrical resistance of that mess.  This is why Mustang fuse boxes catch fire sometimes and/or literally melt or weld fuses.

A view from the back side.

This is the new set of clips.

The first clip has been replaced with a new clip soldered on.

The completed set with the dirty fuse box.

Fuse box cleaned up ready to accept the new clips.

New clips started into their respective holes.

Clips fully engaged. The harness shield back in position.

From the front.  Freshly rebuilt box.

And finally with the fuses ready for service.


  1. First class job, Alex. I tried that eBay link and noticed that they don't include the 68 Mustang. I sent a message asking if they would work. Seems like they should since a 67 and 68 are very similar, but you never know. I'm going to do this with my fuse box. Thanks for the details and photos.

    1. Those eBay clips look like they'd work to me. The only problem is that they're missing the crimp tails and the tabs for the 2 pairs of clips that are connected together so you'd have to solder them which would probably be less hassle anyway. The other issue is that they only send you 9 clips and the fuse box requires 10. Maybe they can be persuaded to sell you an even 10?

  2. Impressive. Are the new clips brass? A dab of white paint on the letters can't hurt so you can see which one is which in the dark. They stick the box up so high in my 66 I almost want to relocate it. Nice job there Alex!

    1. The clips seem to be some kind of plating on brass but aren't overly difficult to solder. White paint on the letters is a good idea. I've already installed the harness but can probably still get some paint on there. Thanks!

  3. Alex, I'm betting you could rebuild a Mustang on a desert island with whatever washed up on the beach. You are one resourceful man!


    1. LOL! Thanks RJ. It would be helpful if the island had an internet connection and UPS delivered there though. :-)

  4. Nice work Alex.......20 days and counting:)Also, send me some pictures of the spot on the fender I need to fix please.


    1. Thanks Steve. I'm actually a lot further along. I just haven't been blogging regularly. I don't know if I'm going to make it by the end of May. I've had some set backs. I took some pics but they sucked. Will try again with direct sunlight later today.

  5. This update came just in time. I lost my instrument panel lights a couple days ago. Guess why ?

    1. Oh man. Sorry to hear that. Are you going to remove the harness to do the repair?

  6. I should have done that, but sanding the contacts was enough for a temporary fix. Thanks to your blog it was easier to locate the correct fuse and clean the contacts instead of first digging out the light switch/dimmer.

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