Joseph Lucas; Prince of Darkness

For many years our TR6 has had this annoying little electrical problem. The car's fuse system consists of exactly 3x 30Amp fuses in a traditional Lucas fuse box mounted up on the nearside inner wing. The 4th fuse holder in the box was a spare, but I have wired this to supply a feed to the socket that the satnav plugs into.


What has been happening is this: driving along quite happily and suddenly, the fuel gauge and temperature gauge go to zero, one of the anti-theft alarms is triggered and both indicators and brake lights stop functioning. The clue is that they are all fed off the same fuse.
As the problem has only been manifesting itself once or twice in a Blue Moon, I've put up with it, thinking for a long time that it was just a badly seating fuse - the clue here being that removing the fuse, cleaning it and replacing it has always fixed the problem.
Until a couple of weeks ago on the Wessex & New Forest event (see earlier Blog entry) when the problem came back with a vengeance. Removing the fuse, cleaning the contacts and poking about with the fuse holder failed to clear the fault. Pulling the spade connector off that feeds the affected circuits gave the game away - 20  years of accumulated grot!

Almost certainly, the other circuits were going to be similar and so as I was going to have to pull the fuse box out to clean it, I might as well replace it with a new part. Which was this morning's little task. The wiring looks a bit of a mess, but it is all very simple and straightforward. It's pretty much as designed by Triumph, other than the addition of the modern relay to work the fuel pump.


For once, I did the job properly and made careful notes of how everything was connected before ripping it apart. The old fusebox was in a pretty poor condition, badly corroded and dirty on the contacts, so that has gone in the bin. The new pattern part actually fitted properly and appears to be as good, if not better quality than the original. Although the original is a genuine Lucas part, so that last statement might be considered as faint praise...


With trepidation, I reconnected the battery and tested all the circuits. Success! Everything works as it should.  And remember the wailing Banshee noise from the last post?  That seems to have disappeared.  I hate intermittent faults!