Saturday, March 06, 2010

It was all going so well until the wiring melted


I set out today to cure the problem of the none functioning oil and ignition warning lights on the dashboard instrumentation.
I had worked out that it was a fault with the backing unit to the instrument cluster and had put off changing it for a spare as I didn't want to disturb the wiring or indeed have to replace it as it differs slightly yet again to later ones.

The photo shows the original 62 one on the left with 2 wires coming from the centre; the black one goes to the fuse box and the green and black goes to the flasher relay. On the later one there is only 1 wire (Green for some reason but actually wired to where the black one goes on the 62) the difference is that the wire for the flasher unit fits on to a spade connecter on the back of the unit at point K (top left) rather than being hard wired into the inside of the unit, so no problem to use a later one, rather than mess about and replace the wiring on the inside of the original one.

So this was all easy, I wired it all up, tested and all was great before permanently fitting the unit to the dashboard. I then put everything back together once I was satisfied that it worked without problem, turned on the ignition and within seconds the car was filled with smoke as part of the wiring loom burnt out. I had knocked the main feed wire off the fuse box and it had shorted out across other terminals and taken the least route of resistance through the thinest wire.

Looks like I have had a lucky escape as this piece of wire is easy to replace and I have plenty of original coloured wiring from the old loom.

My recommendations, tighten everything, check its connected to what it should be before turning on the ignition and ensure you haven't tightened the battery terminals prior to completing testing - I think the ability to quickly remove the battery cable saved the car. Oh yes, and keep a fire extinguisher handy!

video of our 65 on the motorway

video of our 65 on the M40 taken by Paul  Donovan https://m.youtube.com/watch?v=Y5pXVCcqGfA