Morning all, did I mention I had a bit of a problem the other evening? Given these types of cars (kit/replica/plastic/bitsa) are always 'non-standard', every secondhand purchase is not just a bit of a lottery in terms of reliability, but you also have to learn all the quirks of both the car and the original builder's attitude/outlook. In this case, the builder knew his stuff, but the car was built 9 years ago, so things wear and decay. As for quirks, the Start button is also used as an ignition light/charging warning light (common practice, so I'm led to believe). The light seemed to be on ever since I picked up the car (I can't remember exactly when I first noticed it but it was definitely on the 2.5hr drive home) so I didn't think much of it. However, at one point during one of my short local blats I did notice the light had gone off for a bit, but there was no obvious reason that caused the light to be on/off. Random, unrepeatable problems eh? The bane of our lives..
Anyway, a couple of evenings ago I stalled at a motorway roundabout and it was then that I noticed the battery was almost dead flat, unable to turn over the engine more than twice. That was odd because in my garage it started fine. In hindsight it was obviously down to driving at night for the first time and having headlights on. During day running the car was obviously charging just enough to maintain a very slow rate of decline.
So, this is were the 544kg all up weight came in handy - I was able to push it off the roundabout and down the slip road to a layby where a helpful chap sat in his car jumped out and helped me bumpstart it. As I was only a mile from home I kept the revs up and got her home with no further hassle apart from the engine running as rough as a badger's armpit.
My electrical experience, espeically on BMC A Series aengines, is not great, but YouTube, Google and car forums such as here are helpful and I have a multimeter, so I at least managed to work out the alternator was not putting out any charge. I figured I'll just get a replacement as it's only £50. It's a Lucas LRA 100 which is meant to charge once triggered above 1500rpm. The problem being, once the new one is installed, it's still not charging. :-(
Not sure if the new one is duff or there's a wire loose somewhere. No fuses are blown - all have been checked and connections cleaned. Given the odd occasion where the light went out I'm tempted to think there's a short or bad connection. But access to the wiring is limited, mainly due to the car being so small and all the wiring sits under the 'scuttle' (the top panel from the dash to the bonnet), which is tricky to remove.
It may well be the exciter wire on the alternator - I'm getting 0v with the ignition off (correct), but only 6v with the ignition on - surely this is wrong?
- Could I remove the exciter wire and just feed 12v into the exciter terminal on the alternator to see if that tricks the alternator into charging?
- And following that chain of thought, if I disconnect the entire connecting plug (exciter wire D+ and 2 B+ terminals), and get the engine running and spinning the alternator with the exciter wire energised but NO B+ connections (so I can use my multimeter), will I damage the alternator?
I'm unable to trace where the exciter wire goes at present but presume it has to go to the Start button/ignition light. I'll try and remove the scuttle today (no easy task) to get to the wiring. Luckily the PO gave me a data stick of all the photos he took during the build, which helped him get past the IVA test..
One from early in the build (tan dash and black steering wheel):
One from later in the build (black crackle paint dash)
At least it's well laid out and pretty simple (once I get access).. Fingers crossed.
Any help offered on exciter wires and charging shizzle gratefully welcomed as always! :-)
Cheers, Martin
