Control box

[P3Steve]

Looks like the control box on my P3 Rover is playing up on tick over it shows about 10 to 11 volts but as soon as the revs go up it jumps up to 20+ volts and when it returns to tick over the volt meter sticks at 20+ volts for two to three seconds then drops down to 10 to 11 volts again, any one know of any way to adjust/clean or service these if not dose any one know of where one can get one it’s a Lucas 9 post 12v type RF95. Holden classic car sells one for £99 ex vat here’s the link

http://www.holden.co.uk/displayProduct.asp?pCode=RF95

Any one know where else I might find one or if it can be repaired? Thanks for you help. Steve

[paul williams]

Hi Steve,

the following may help

http://www.thersr.org/uploads/Lucas_Control_Box.pdf

or

http://www.thersr.org/uploads/Lucas_Tests.pdf

I have worked on a few of these, before attacking the control box, make sure the dynamo is working properly. This means checking with open and shorted field windings. Also check the battery is fully charged, ie only taking a few amps on charge from a battery charger.

The rf95 itself is a simple unit, the circuit is in the attached pdf and also on the Holdens link, check for continuity through the coils, this involves unsoldering some connections and also check the value of the resistor. The resistor can crack and age it can be replaced with a modern equivalent. Finally if all seems OK clean the relay contacts with fine emery paper and lots of WD40.

Hope that helps

[P3Steve]

I mentioned volt meter in the last post but I was working off the dash mounted ammeter but as I've not had a lot of time today after work I settled for cleaning the terminals with WD 40 and fine emery paper as you suggested and it dose seem to be a bit better on tick over it reads just under the zero and now when you rev the engine the ammeter rises and falls with the engine revs and only go's up to the 20+ point on high revs it also dosnt stick like it used to dropping as soon as the revs do, there is a chap I know who is an auto electricion who is going to go through the whole system for me but he cant do it until next week so I'll keep you posted when I get it back from him.