Charge light dimly glowing - alternator issues

[Ozdunc]

Regardless of revs the charge light does not go out on the dash. Very faintly glowing.

Its a 14AC with internal regulator, so just the B+ and IND terminals.

Battery is 12.6V not running, 14.2V running at ~2000rpm, and 13.5V under load (with halogen lights,wipers, washer motor and iphone off the 12v socket) at ~ 2000rpm

I've checked the chassis to engine strap, and all seems solid.
I've also checked for voltage drop across the ignition switch by turning on the indicators (light stayed dimly lit, no pulsing).

Charge light went out with ignition on (but not running) when I disconnected the IND spade, so proving continuity of the wiring between the ignition and the alternator on the exciter feed.

Brushes are 600km old.

Are there any more checks I should do before dumping this alt?

I'm thinking of upgrading to a 16ACR as they seem cheap and easy to get hold of.
Other options could be to use a A127 45amp alt off a 2.5 90/110 or a Bosch unit (which one, and any idea of prices?)

[bee utey]

The dimly glowing charge light simply says there's a voltage drop between the alternator output and the ignition circuit where the globe is connected. If any of the wiring/switch gear between the battery and the ignition circuit is poor that's where your loss will be. Alternator diode faults tend to be shown with a stronger glow, about 1/2 that of the glow when the engine isn't running. Basically if the battery charging voltage is normal you're OK. Upgrading the feed wires to the ignition switch may help other loads cope better.

You could possibly run a relay to power all of the ignition circuitry off its own heavy battery feed, using the ignition switch to just energise the relay.

[Ozdunc]

That's handy to know.
The glow is faint, its really an orange S there's no luminance coming from the bulb whatsoever.
Unlike with the ignition on and not running, its bright.

I've thought about having a relay for exactly that before, this might be the trigger for me to actually do something about it

[PhilipA]

Run a starting jumper lead first from the alternator body to battery negative and see if the light goes out. If so it is an earth problem.
If not then try the lead from the positive (carefully) on the alternator to the battery positive.
If in either case the light goes out then it is a wiring resistance problem.
Regards Philip A

[Ozdunc]

Thanks Philip.

I'm thinking the best way to connect positive to positive, would be to disconnect the -ve battery terminal first then reconnect.

Gives me something to do this weekend ;)

[Ozdunc]

Followed Phil's advice (simply because I'm lazy and it was easier than trying to trace an ignition wire in the rats nests I call a loom), but no difference.

I did find two wires joined together to a spade connector ( live) behind the dash. The ignition still has a live feed , but I think these wires might be A and A1 from when it had a dynamo, so I plugged that to the ignition feed as well.

I still have a faint glow up to 1500 or so, then it goes out. I reckon Bee Utey gets the LR diagnosis badge of the day.

Another reason to think about re-wiring...[bigwhistle]