Friday 25 January 2013

Electrical Power Re-established

The lightweight alternator installation is finished - well, finished apart from locking the adjustment bolts.

Today I ventured out into the only-just-above-freezing & wired it up. Of course this turned into a saga as my engineering oft does. When I built the car with the Lucas alternator I used some red wire I believed to be thick enough & ran it buried nicely inside the wiring loom. After a while & after a few alternator related problems, I suspected the wire was perhaps a little thin, so I added an additional wire - which made no apparent difference at all. Hence the long project of fitting a modern, more powerful & 2Kg lighter alternator.
Job one was to take the driver's side pod off as the battery & the cut-off switch I'd need to wire to are hidden in there. Then after a fair bit of wrestling, I removed both the existing wires, crimped & soldered one end of the new wire, gave it three layers of heat-shrink to strengthen the join, then hooked the new terminal over the wiring post & looked for a route back.

The obvious route took the cable close to the inlet manifold & throttle bodies, as I prefer the electricity & fuel to mix INSIDE the engine, I didn't like the look of this, so instead I ran the wire outwards & round the alternator, holing it on p-clips attached to the bolts that hold the alternator body together, then when well away from stuff, turned it rearwards to clip to the chassis. Next problemette was the cut off switch. This has ENORMOUS terminals (10mm post) & I had previously made my own connector by soldering all the wires into an 8mm copper pipe, wrapping copper plate round that to make a "tag" & drilling it 10mm. It's worked well, but I wanted something a little more elegant, so made a plate from 5mm aluminium drilled 10mm one end, & with two 6mm holes the other. I again crimped & soldered the alternator wire, the other wires (supplying the ignition switch & the fuse box) also got crimped & soldered into a new terminal, more heat-shrink, a 6mm bolt, nut & washer & we're done.

I left the second hole open in case I need a permanent live for something in the future, I'll insulate it before I put the pod back of course. So the last couple of wires are the blue one that feeds the "IGN" lamp & unlike the Lucas, this new alternator needs a switched live. Fortunately there was a spare one in the engine bay, not a foot from where I needed it. This used to supply the coil in the days when the beloved Crossflow was in the car, but had lain neglected & unloved since then. Now, with a new useful life in prospect, it got extended to reach the back of the alternator, & in company with it's new blue & red comrades was wrapped in split conduit, fitted to a shiny new connector & clipped into the alternator. I turned the key in the ignition - nothing. I turned the master switch on & tried again (doh!), two lights lit, I pushed the starter button, the engine fired instantly (the Crossflow may have been beloved, but it never started like this) & equally instantly both dash lights went out, the oil pressure hovering around 60psi, the volts a smidge below 14v - considerably better than the 12.75v the Lucas would make. So as it was really far too cold to be outside, I repaired to the house, leaving the last of the wire tidying for a warmer day.

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