Skip to content
Aussieveedubbers

generator light

0 likes
Share Share on Facebook Share on X Share on Reddit

71dub Officially Full-On Dubber

361 posts · joined Sep 2008 ·

#1021294
Hi guys i have a 1971 super bug and when increasing engine revs the generation light comes on .when at idle light goes out.have replaced battery and replaced generator brushes .A thoughts would be appreciated.Thought may be earth problem .

ragged Just ask if you need HELP!

478 posts · joined Jan 2005 ·

#1021296
Voltage regulator. It's under the back seat.

AA003 Custom Title Time!

1,189 posts · joined Oct 2011 ·

#1021308
Could be a few things but you need to check everything wirh a voltmeter first before you waste time/money.
I read it on samba, so it must be correct.

Sometimes Volkswagen dealers sell spare parts. Amazing isn't it!😂

psimitar Son of Jim - Creator of Good

2,506 posts · joined Jan 2009 ·

#1021324
Yea could be be as simple as a loose connection or bad earth so if you have a voltmeter then check online for how to do a voltage drop check on the charging circuit wires and also take a look at Speedy Jims website from USA. He has lots of useful electrical diagnostics for you to follow and will also tell you how to check the alternator/genny is working properly.

No point spending on a new regulator unless you really have to cos the quality of them is crap especially for the price you pay for them these days.
madness is in the eye of the beholder 👍

71dub Officially Full-On Dubber

361 posts · joined Sep 2008 ·

#1021365
Hi guys well sent some time at weekend and replaced worn generator brushes ensured battery fully charged checked operation of generator and is charging correctly .checked voltage regulator and is charging correctly .cleaned battery earth at body and at battery cleaned earth at gearbox to mount under the car .But am still having the generator light come on when engine revs increase.Thoughts

psimitar Son of Jim - Creator of Good

2,506 posts · joined Jan 2009 ·

#1021368
Did you check the voltage to the battery as you revved the engine?

12.2-12.6V is normal for engine off and 13.8-14.6V is good for the engine running. Being a genny it will probably be at the lower end at idle as they don't produces peak voltage until somewhere between 1500-2500 rpm. Can't remember exactly but if you see the voltage at the battery drop back down to what it is with the engine off then it's either the regulator or possibly the windings in the genny breaking down.

Speedy Jim has a tutorial for checking the genny when not connected to the regulator and if that checks out then regulator is the only option.
madness is in the eye of the beholder 👍

AA003 Custom Title Time!

1,189 posts · joined Oct 2011 ·

#1021382
It could also be a faulty ignition switch or ignition circuit.
I read it on samba, so it must be correct.

Sometimes Volkswagen dealers sell spare parts. Amazing isn't it!😂

southspark Seriously Crusin Dubber

130 posts · joined Mar 2007 ·

#1021385
The generator light has two supplies, one from the generator the other side of the light gets an ignition supply via the ignition key and a fuse .Check your ign. fuses either for blown or corrosion.
regards Paul

71dub Officially Full-On Dubber

361 posts · joined Sep 2008 ·

#1021389
Thanks guys am slowly working through the suggestions before parting with hard earned cash will keep you up to date

psimitar Son of Jim - Creator of Good

2,506 posts · joined Jan 2009 ·

#1021411
IIRC the ignition supplies 12v to all 3 of the dash lights. Oil, Genny and indicator. Each bulb then has a switched ground to make it light up. In the case of the oil it's the sender unit and oil pressure breaks the switches contact to earth.

For the genny the regulator earths the dash bulb until voltage is produced by the genny which then breaks earth contact and is also trying to feed 12v to the dash bulb. As there is no earth anymore then the light cannot light up 🙂

So long story short I think it unlikely to be an ignition switch problem. Not that it couldn't be but pretty unlikely.
madness is in the eye of the beholder 👍

71dub Officially Full-On Dubber

361 posts · joined Sep 2008 ·

#1021489
ok guys up date generator brushes not bedded in .took to auto electrician to get checked generator light didnt come on at all .charge rate checked and regulator checked all ok .All put down to not cleaning commutator before installing new brushes .All fine now

psimitar Son of Jim - Creator of Good

2,506 posts · joined Jan 2009 ·

#1021495
Ah padowan. Lesson learnt. Always a good idea to clean the commutator of any motor when replacing the brushes and I have socket attachments for my drill so I can spin up the motor/genny to help bed the new brushes in 🙂
madness is in the eye of the beholder 👍