11 AC Lucus Alternator

#21
So at least I'm learning stuff.....
I realised I was doing the current test incorrectly. I'm actually losing 2.3 amps (WTF!?). That seems like a lot to me. No interior light, no boot light. Pulled each of the 4 fuses one by one, no change. Checked the feed for the (missing) radio wasn't earthing - nope. I guess I just go through under-dash stuff one by one somehow? Does the fuel gauge normally read with the ignition off?

Would a fault in the 6RA, 3AW or the 4TR cause a leak like this? As the other symptom was the lack of charge I'm suspecting one of these other components. Will have to research how to test them.....





....well that went faster than expected. I disconnected various things one by one until I got to a small silver box inside the passenger glove compartment where I was expecting to find the 4TR....but this box only has two wires, both yellow. One has a blue connector and one has a yellow. When the blue connector is removed, my leak goes back to .02amps. TADA! Now, what the @#*! is it? I can't upload photos at the moment, but it's a small silver box a bit larger than a matchbox (remember them?). On the top is 'Ashdown' No. 45-30503.




.........So I googled Ashdown - they still exist. AND there's a local retailer....AND he matched it to a current stock number - external voltage regulator. Will have a new one come monday!! I'm feeling good to have learnt how to use my multi meter, diagnose a fault, find the fault and be able to get a part. That's a win for me.
 
Last edited:
#25
So the new regulator went in. Now it's not charging. Haven't measured drain yet.. is the diode rectifier in the alternator? I might have to throw in the towel and take it to a sparky. I'll be pissed if it's the alternator, as I just had that in there.....
 
#31
There's no bulb in the boot light. So frustrated with it right now. I don't understand how all the parts work together which makes diagnosing it very difficult. Is there any way to see if the alt isn't being triggered to charge or something like that? Sparky said the alt was good - and it was working when I got it back...but it's not now....GRRRRRRR :(
 
#33
Hello sorry if this has already been posted i have looked back but not found yet
I have a 11 AC Lucas alternator and I am not getting any output
Charge light on dash illuminated and no increase in voltage at battery when engine running before I go out and replace it is there anything else on a series one 3500 that I should look at before replacing alternator
Thanks Roy
 
#36
Saga continues. Relay appears to fire up, so not that. Then magically the drain left and the alt started charging...then just as magically the drain re-appeared, but for now, the alt is still charging.... With an external regulator are there diodes in the alt that could be playing up intermittently??? Could a loose battery post on the alt cause a drain?
 
#38
What is the job of the 6RA relay? If it's not turning on would the alternator not charge....I guess? Is this an accurate diagram for the 6a? Durite 0-727-20 Relay, 12 Volt 30 Amp, 6RA Type Make or Break Relay


I guess I could just try one of the modern relays hanging around and see if that works.....
The relay is switching the field windings into circuit when the ignition switched on. If not working the alternator will not charge, if latching on with the ignition off it will discharge the battery
6RA is the generic Lucas designation for that type of relay and the Durite is a copy , the circuit is correct for a standard 6RA
 
#39
The relay is switching the field windings into circuit when the ignition switched on. If not working the alternator will not charge, if latching on with the ignition off it will discharge the battery
6RA is the generic Lucas designation for that type of relay and the Durite is a copy , the circuit is correct for a standard 6RA
Thanks, that really helps! It actually explains why the problem is intermittent. Sometimes it's latching, sometimes not. The drain IS through the field circuit so it also explains that. And it explains why the drain is sometimes there, and sometimes not. I did try a modern relay but the car wasn't happy with it, so I might try and get a new 6RA....and see if that helps!
 
Top