Lucas Voltage Regulator RB 340

[pburgess000]

I have some charging problems on my S4 Elan, in that the ignition warning light flickers at low revs and on occasion the battery is flat even after a run.

The output from the dynamo seems fine, so the easy, cheap fix is to swap the Lucas RB340 voltage regulator.

There seem to be several versions of this. I am not clear whether I need to worry about this, as visually they seem identical.

Does anyone know the answer?

Thanks

Peter

[zog]

Try cleaning the contacts. Especially the normally closed contacts. I use my wife's old used sandpaper nail file.

[Jason1]

Hi Peter

You need to take the black plastic cover off and count the bobbins.

RB106/2 (2 bobbins) on my +2 with spade connections. 12 volt, 60 ohms and 22amp setting.

Would this be the one you need?

http://www.ebay.co.uk/itm/NEW-Voltage-r ... 617wt_1037

Jason

[pburgess000]

Thanks guys, some good tips here. I shall investigate under the lid.

Cheers

Peter

[ricarbo]

According to the AES site, the RB340 3 bobbin design comes in three different maximum currents, of 11 amps, 22 amps and 25 amps. I believe you should use the 25 amp version, but may be wrong. Presumably depends on the dynamo it's paired with.
The RB106 2 bobbin model is an older design in a different case and i think it is 22 amp. My recollection is that the third bobbin of the RB340 is for current regulation, and it gets a bit more out of the dynamo than the RB106.
Personally, i find these difficult to set up right. the adjustments have to be made quickly, before the unit heats up, so you may have to have several goes at it, with a suitable cooling off period. So I'd be inclined to put in a new one, bench set and guaranteed.
Richard

[pereirac]

Has anybody tried a 'solid state' replacement?

http://www.dynamoregulators.com/dvr3.php

Carl

[pburgess000]

Thanks everyone. As a brand new replacement is under ?25, it seems a worthwhile route to go. I wil let you know if it makes a difference.

Peter

[ricarbo]

I think I would keep the old one for possible attention at a later date, just in case the new one proves to be a cheap and nasty copy.
Richard