Classic cars forum & vehicle restoration.

[7777]

Hi, just wondered if anyone on here had any advice.

One of my MGBs had its starter motor stay on, which caused the wiring harness to overheat. The wires are still operative, but fused together.

I'm looking at putting in a modern system of relays and fuses (1979 being a great year for tennis, but not for electrics) and just wondering if anyone had done a similar job on their classic car.

I'm sorely tempted to rebuild an entirely bespoke system using modern switchgear, relays and so on, with the requisite replacements in the wiring loom itself. I'm competent enough to undertake the work and money isn't an object, so what would you [plural] do if you had the opportunity?

The main thing I'm concerned about is putting a spare ignition coil into the loom. I always carry a spare in the boot, anyway, what with it being British.

So, to recap, starting from scratch and with the intent of building in multiple redundancies. Ideally, if it's capable of doing the Carrera Panamerica then that's what I want to do. ie something which is rugged enough to cope. Mainly because I racked up 30k miles in that car back when I bought it in 2010 during the FIFA World Cup and October of that year (I do a lot of miles. No kidding), before putting it on snow tires and thrashing around the Alps that winter. Good Times...

[Farmer John]

Hello. As you probably are aware, electrical systems are notorious for transposing cause and effect.
Just suspicious of the exciter wire actually melting the loom.
If previous owners have wired in stereo, driving lights or other accessories that is a good enough reason to want to discard the loom!

John

[7777]

Yes, there was a poorly wired stereo! It wasn't even properly affixed to the bracket... I've had to redo an entire wiring loom on a BGT in the past, not much fun I can assure you.

In this particular case, the original BL ignition key was missing the last 10mm of the actual key itself and the ignition barrel allowed it to stay on in the 'start' position [III?] and kept the current flowing.
I haven't checked to see if the motor is burnt out, but given that the wires are now 'as one' I'm guessing it probably is.

I'm going to strip out the original barrel and put a series of switches onto the dash, but I'm pretty certain that the barrel allowing the III position to stay open is the cause - I only noticed 2-3 miles down the road when she cut out altogether when the coil failed. I swapped out the ignition coil and that did the trick (with a running bump start - thank God MGBs are so light!) so I'm guessing that the coil got burnt out as well at the same time.

This is why I always carry a spare coil, dizzy and alternator...been driving these lovely cars for 16 years now and it always seems to be the usual suspects that fail...British foibles, eh?!