Thread: New Isuzu Owner

It seems to me that you still have a regulator problem but I am no auto lecky. Hopefully someone one here who is one will chip in. Anyone out there!

Yep Brian is correct you have a crook voltage regulator. If you dont fix the problem you will have a spate of blown globes and any electronic gizmos wont like it either!

Originally Posted by Distortion

Hi,

Got out there with a decent volt meter rather than the gauge in the cab
New Alt New Reg

I get 12.4 with ingnition/motor/everything off

motor at cold idle 13.4 which is good
move it up to about 2000 rpm and volt meter shows around 15.4V

with everything I can think of on headlights wipers indicators internal lights etc on it varies between 15.1 and 15.4

Thats both at the battery and at the alternator.

cab gauge is showing over 16 at this point but I the volt meter shows thats inaccurate.

not really sure how worried I should be about the higher voltage however given I sit over the top of the battery I don't really want it boiling/exploding right beneath my ass

Is the regulator earthed properly?

it's definitely possible the earth is bad, but new voltage reg and I'm pretty sure I've got the earth connected correctly

Would there be any way to test this
ie ignition on then volt meter between some pins on the plug ?

cheers

Rob, I've been through a very similar process to you but my original regulator failure was a bit more obvious than yours (see below). The original was solid state but the only replacement I could find was the same RGX4023 that you also found. This regulator is a step backwards into the mechanical era. And, guess what, mine also runs up near 15Volts. I'm pretty sure this is a fault/characteristic of the regulator. I've opened it up and there is no adjustment available. I did have a go at bending the spring on the top of the voltage regulator relay to make it a bit firmer (and hopefully lower the voltage) and this reduced it for a short period then it crept back up to the 15Volts. So maybe I should get a bit more agressive with the "adjustment". Its a low priority at the moment but I'm considering buying a generic solid state regulator or the 70A internally regulated alternator (I'm still running the original 40A). So its not conclusive, but I'd suspect the regulator.

BTW, it's probably just the relay on your original regulator that has died (I think this is what drives the charge light). It may be repairable and may regulate to the correct voltage.

Pete

This is what the regulator looked like when I bought the vehicle. Surprisingly, it didn't work.
Voltage Regulator.jpg

Is the new one internally regulated? Having both may be causing the problem.. I have an internally regulated one, and the original external regulator and I got 15.4v.. I don't know where the volt sensor is v
Fed from but the new alt may be different causing the prob.

Ok you guys need to adjust the voltage regs

Captain Slow the reg you posted full of rust is adjustable the small squareish surface mount trim pot has a phillips cross bit receiver in it which can be turned by a small phillips head screwdriver i had the same reg in my old 240k datto and i probably have the same in my county .

Start the engin with the cover off the relay and bring the revs up to about 2k then wind back the trim pot till you get about 14.5 V at the alt and your set

Ok i just re read this and the gemini type is the old school jobbie which you ned to bend the the arm in with pliers dont be light with it either give it a good bend to adjust it tho its old school it will probably outlast the later ingram solid state jobbie