Fuse Panel Connector Failures:

A few months ago I repaired some burnt tracks on the fuse board of my blue Testarossa and have been running around with that board in my red car for testing purposes.

I've had a few issues with the car of late, and after replacing certain components I was able to diagnose faulty RH fuel pump as the cause. Sure enough, another damn connector had parted ways and burnt another section of the Y white plug. Strange that it was only drawing 9amps and cooked the plug, yet its mate right alongside it and running the other fuel pump is only drawing 8.3amps?

Anyway, I pulled the old connector out and replaced it with a 4.2mm blade connector which was seated firmly onto the factory pin and away I went, all happy again.

On the weekend I drove the car both days out to functions and all went well until I left the luncheon on Sunday on 6 cylinders again. Reaching into the fuseboard and 'jiggling' the RH pump wire it would run intermittently. I did some roadside wiring and managed to get the pump running and drove home.

This morning I pulled the fuse board for a closer inspection and found that the pin had actually come adrift from the board, hence the intermittent contact.

For those unaware, the pins have two 'legs' on them about 1.2mm wide that fit into two small holes in the face board of your fuse panel where the relays push in. These legs penetrate the various layers of the board and are soldered to the copper tracks on the various layers depending upon their position and connections. Apart from the small area of solder there is nothing else actually holding the pins apart from the two small holes. If these pins get really, really hot, they can burn the face board; which mine has done; and can be pushed into the board which could cause some serious issues!

I'm a bit over this whole board repair issue and it comes back every time to two issues.

1) The connectors are crap and give up after years of use, particularly on the 6 'high' drain circuits. This creates massive resistance which in turn creates heat and the boards and connector plugs burn.

2) Many of the actual appliances which run in the car are also aging, particularly those with electric motors in them. Fans, pumps, windows etc. As they get old they tend to draw more amperage than when new so these appliances must be serviced, repaired or replaced to bring the current loads back to within factory parameters.

Basically, if you get rid of those crap connectors, and ensure that all of your appliances are serviceable and in good shape, then you simply won't have any further issues.

I have already done oil fans, radiator fans, window motors and a few other things, so today I decided it was way past time that I got rid of those damn connectors once and for all.

First step was to review the options on F-Chat to get a good grasp on the issues and see what others have done to rectify the issues.

Shamile in Florida has had a go, but the problem with his fix is that if you need to remove the fuseboard to get to a relay behind it, the job of removing all of those individual connectors is a bit tricky. Add to this that as you push the blade terminals back onto the pins, you run the risk of pushing the pin through your board which is what happened to me on the weekend.

There have been a few other 'fixes' and some look great, whilst some look a bit ordinary. Dave Helms is doing great work on his 'kit' and I had a good look at that. He's needing to make a kit that suits every need, slight burnt, couple of loose pins right thru to crispy fried. Hence the new relay banks and separate fusing requirements. Looks great, hides away and I'm sure it works perfectly. Dave offers a quick turnaround and fits his kit to your fried boards. Not too easy for me though. I'm in Melbourne, he's in Colorado. This won't be a two day turnaround for sure, especially at this time of the year.

I had a good think about it and decided to have a go anyway.

Firstly I removed the board and opened it up on the bench. I removed my old track repairs and then soldered 2.5mm/sq wires directly to the relay pins on the back side of the circuit board.

Then I drilled six 3.75mm holes into the side casing of the actual fuse board and fed these six wires out of the board.

Next was to climb into the front boot and remove the six offending wires from the factory loom and lay them to one side. Then I could refit the board and do the external connections.

I purchased a quality 6 pin male / female plug and fitted this to the new wires and also to the six offending factory wires that head off to each of the 6 problem appliances. Once I plugged it all in, I now have good solid 6mm blade connections with a 25amp individual rating, all running through one nice 6 pin white plug. If I need to remove the board, I simply remove the factory connectors, pull my white plug and the board comes out exactly as before.

I took the car for a good run. It's 30 deg C in Melbourne today so I got everything to run except the oil cooler fans. Must have to be damn hot to get them to run.

I checked the new wires, plug etc and all was great. Barely even warm.

My fuel pumps are still pulling 9amps and 8.3amps, radiator fans pulling 14 and 11 amps.

I did the AC circuit and oil cooler fan circuits as well so will check out the draw on them when I fire them up. Probably have to jump the relay on the oil cooler fans as it just never seems to get hot enough to make them work.

Here's some pictures of the days work.

Here's the board refitted with the new plug visible and also the 6 culprit wires also coming out of the left side of the board now.

And here's the finished plugs. Simply tuck them away down the left side where they fitted perfectly. Access is great to get to the plug and undo it if needed.


Follow this link to download the complete wiring and pin-out diagram for the Testarossa.

Wiring Diagram.pdf

Updated December 16th 2009

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