|Fuse Box Repair Page Two:|
|Well second stage of the repairs
started better than the first. At least the wiring colours and
language problems were sorted out.
With the boards all separated and cleaned it was time to commence repairs. The damaged sections of board were covered with the teflon tape and then all holes had to be replicated. A nice new 1/16" drill bit mounted in a high speed battery drill was perfect for this. For the larger 3/16" holes I used a leather punch set over a hardwood block and an engineering knockometer. If the copper track had lifted away, I simply glued it down with Loctite superglue as previously described.
This image shows boards one and two. Board one is the final layer. You can see the teflon tape used to patch the damaged board.
Here's the other side showing the final pins left on circuit board one.
Once the tape is applied it is vital to clear all of the holes, both for the following pins to protrude through, and also for the soldered joint heads to poke through and not disrupt the flat surface of the board. Use a hole punch and a small drill bit for this.
When all of the boards are repaired and the holes have been chased through, it's time to start re-assembly. Make sure that all of your pins are clean and any solder 'dags' are removed so as to allow the pins to pass through the mount holes easily.
Start by laying board two over board one. Locate three or four pins or fuse holders on various places on the board and solder into place. Ensure that you use a very fine jewellers style screwdriver to keep pressure on the board as you solder. This ensures that the boards are properly compressed together and kept flat and tight. You have to be careful or you will end up with your laminated circuit boards looking like Grandma's bed with 5 thick quilts instead of a nice compact layered board with near invisible joins.
Here are boards two and three, repaired and fitted back together.
This is a very time intensive job and can be a bit hard on the eyes. You can't afford to make a mess of this so if you are getting weary, take a walk and come back to it when you are refreshed. It took me about 6 hours to effect the board repairs and re-assemble the pins. Try not to get too much solder flux on the board. I know this can be quite difficult, especially when you are using a lot of heat and sweat soldering to a heavy track circuit board. In this case the flux tends to run and it's easy to get air holes and pits. I use a small brass wire brush; no bigger than a toothbrush; to clean each joint as I went. If pitting was evident I'd simply do that joint again until I was satisfied.
Between each layer and in addition to the tape I have used a clear lacquer electrical spray which is available from most good electronic stores for a few dollars. It's a quick drying and leaves a nice non conductive layer between each board during re-assembly.
Here's board five, soldered, sprayed and all finished ready to be mounted back into the relay / fuse frame.
Here is an image of the completed board showing all pins back in place and the right side fuse block mount going back on.
As it is still not totally evident as to the cause of the excess heat I decided to take further steps to prevent reoccurrence. I located the pins that had caused the problem and after tracing them through the boards, I decided to run a hardwire from point to point on certain pins. The theory here was that if the board was showing it's age and was unable to cope with high amperage demands, I would assist it with a few strands of 4mm automotive electrical wire. Here's the completed board mounted back into the frame and showing the heavy wire connectors.
And finally, after nearly two days of work, here is the completed board, repaired and strengthened, ready to refit back into the car.
Now that the first part is over it's time to climb back into the front trunk and repair the burnt pins on the large white plugs. At least the back of the work is well broken. Tune in tomorrow for further updates.
Follow this link to download the complete wiring and pin-out diagram for the Testarossa.
|Updated January 9th 2007|