97 Trooper dash battery and 4WD lights don't illuminate before 'start'

[boritz]

1. Dash battery and 4WD lights don't illuminate when the ignition key is turned to 'ON' prior to starting. They do illuminate when the alternator 'L' wire is grounded with ignition key 'ON' - therefore the globes and connections OK. The 4WD light does illuminate when 4WD is selected. The other dash lights do illuminate before start - CEL, Brake, Oil.

2. Auto-electrician has just replaced the alternator bearings and brushes - the dash lights were OK before this! - I'm not blaming them - I removed and installed the alternator.

3. All alternator component parts pass the electrical checks as per Isuzu manual.

4. Alternator is charging - about 14.5V across battery with motor running - and dash voltmeter is reading the same - and I've driven the vehicle for over a week without getting a flat battery!

5. 'L' and 'IGN' wires show 12V with ignition 'ON'.

6. Regulator 'L' and 'IGN' terminals, without power, show continuity to ground.

7. When 12V is applied to the regulator 'IGN' terminal, the 'L' terminal also shows 12V. This may be the problem - I would have thought that it should still show continuity to ground to illuminate the dash lights until the alternator is running?

Any informed opinions would be very much appreciated.

[boritz]

Can anyone advise the ohm value of the 'L' terminal-to-ground resistor as indicated in the later-model circuit diagram via the link below?

http://forum.australia4wd.com/index.php?act=attach&type=post&id=7475

Also, is anyone with a later model able to identify where the said resistor is physically located?

If I attach a 12V globe where the resistor would be if my vehicle had one (which from new it never did) - everything works correctly!

I suspect the regulator is dodgy.

Checked everything as per the manual again.

Same problem. With IGNition ON there is about 9V at the 'L' terminal, preventing the battery warning light from illuminating.

If the 'L' circuit is grounded - the light comes on.

Alternator is charging OK.

Any comments much appreciated.

[boritz]

Prognosis: had the alternator checked by auto-electrician. It was indeed a faulty regulator.

My Aussie electrician was not able to source a replacement regulator (yes - I believe him). He was able to supply a remanufactured Denso alternator for AU$420 (US$360). I fitted it and voila - all OK now.

Interestingly, I checked www.rockauto.com and a regulator is more expensive than an entire remanufactured alternator!

For any interested Oz readers: replacement was OEX by ENDURO RX A447 SFAH P 585.