Hey fellas, I recently got myself a Datto 1200 ute and having a bit of a problem with it.

The charge light comes on when i start the car up, and comes on mainly when i start it.

I have replaced the alternator, regulator, and the belt has adequate tension.

Any ideas?

Cheers.

any help appreciated

Idle could be too low, I dont think the alt will charge under 600rpm~. This happens with my partners auto if its really cold and the chokes off. Does it go away if you rev the car?

Is it a coupe dash? maybe miswired? I've not compared the late model round-dial 1200 ute dashes with the coupe ones to know if the dash loom and dash electricals are different to that of the coupes in the early 70s.

Find the "L" terminal on the alternator and test it. It should be earthed when not spinning, and not earthed while the engine is running. If you have an external regulator, you will have to push a pin into the L wire (red/white) and check continuity to ground with engine on ignition, then start engine. continuity should break once engine starts. The other wide of the light gets 12v from the brakes etc, and comes from the 10amp ignition fuse.


EDIT:

You've replaced alternators..but not regulator... Put a voltmeter across the battery. Then rev the engine. If the volts go up..your regulator is blown (very common).

EDIT2: damn you replaced the regulator Run my tests.

Thanks mate,
I'll get hold of a voltmeter and check it out.
As far as I know its standard (dash) round dials. Its a 1981 model "nissan datsun 1200" nissan badges etc.

Cheers for your help.

let us know wat the problem is when u find it as my car does this as well..

Some alts. do need a bit of revs to start charging,if you rev it up and the light goes out ,does come on again on idle?

haven't had a chance to check the alt. yet,

the charge light usually comes on when ive just started it, it usually clears when i rev it up a bit, however it comes on whilst im driving down the highway as well...

Most noticable when using headlights, the charge light comes on, the headlights light up extra bright....
the charge light goes back off, and the headlights dull back down...

sometimes it stays on for a long time, sometimes it flashes erratically...
sometimes it doesnt come on at all??

I'm not 100% sure but i think also when its really bad (constantly coming on & flashing, and headlights constantly flashing) it feels as though the spark plugs arent getting enough voltage and it starts to stutter a bit

cheers for any help fellas

From your description, sounds like a dud battery and that your engine is working primarily from the alternator only. battery is only holding a minimal charge.

if the battery was that bad then it wouldnt be able to start a car...

The alt warning light is earthed via the external regulator, not the alternator. The alternator drives the regulator warning lamp circuit via the neutral {star point) connection within the alternator stator windings. The lamp coming on and the headlights becoming brighter at the same time usually indicates a faulty wiring connection between the neutral output at the alt and the reg. at this point, the reg thinks teh alternator is not charging, increasing field current and thereby increasing the charge voltage to compensate, while at the same time bringing on the warning lamp. Check/ rewire the 3 wires between the alt and reg and your problem should clear up.