charging problems

Semi Hemi · Post by **Semi Hemi** » Mon May 09, 2011 7:48 pm

hi again,i've just fitted a new voltage control box RB106 and wired it up like this A1 ignition,A battery,D dynamo,F field and E earth thing is i've got nothing coming out of the dynamo,should i have a live at the field terminal when the ignition is turned on? the readings were taken at tickover

JSF55 · Post by **JSF55** » Mon May 09, 2011 8:55 pm

Polarized the generator ?
http://herald-tips-tricks.wikidot.com/e ... -generator

Semi Hemi · Post by **Semi Hemi** » Tue May 10, 2011 4:29 am

ahh nope,ill do that tonight..
thanks

DaveEFI · Post by **DaveEFI** » Tue May 10, 2011 7:30 am

JSF55 wrote:Polarized the generator ?
http://herald-tips-tricks.wikidot.com/e ... -generator

Weird article. I've never know a dynamo need polarising after the battery has been disconnected - you do it once with a new dynamo, or to change its polarity. I've seen barn finds where the dynamo hasn't been used for 20 years which still work.

The normal way is to disconnect the dynamo, link the two terminals on it together (output and field) and briefly apply the 'live' side of the battery to them. If the fan belt is off, the dynamo will act like a motor.

Also, the majority of UK cars you're likely to find (post WW2) with dynamos were built positive ground. Exceptions were Rolls and some Rovers. Of course many will already have been converted to negative ground to allow the use of modern ICE or other electronics.

Unless originality is important, I'd convert to an alternator. Modern traffic where headlights are used at all times when lights are needed is usually too much for a dynamo, which won't balance the load at idle. Also, you can buy (at a price) alternators fitted to the original dynamo body, so it will look the same.

Semi Hemi · Post by **Semi Hemi** » Tue May 10, 2011 6:48 pm

yes i've seen them altenator in a dynamo things and at around £400 ill give them a miss,well ive wired the D and the F on the dynamo together and it works like a motor so in guessing its the control box??

JSF55 · Post by **JSF55** » Tue May 10, 2011 8:16 pm

I've heard bad things about those alty/dynamos, they tend too cook themselves?
googled this, getting the voltage required might be a problem tho ?
http://mgaguru.com/mgtech/electric/et121.htm

Semi Hemi · Post by **Semi Hemi** » Tue May 10, 2011 8:34 pm

JSF55 wrote:I've heard bad things about those alty/dynamos, they tend too cook themselves?
googled this, getting the voltage required might be a problem tho ?
http://mgaguru.com/mgtech/electric/et121.htm

thats great thanks..i think

ill have to read that a few times

DaveEFI · Post by **DaveEFI** » Wed May 11, 2011 7:19 am

Semi Hemi wrote:yes i've seen them altenator in a dynamo things and at around £400 ill give them a miss,well ive wired the D and the F on the dynamo together and it works like a motor so in guessing its the control box??

That will have polarised dynamo if needed. And if it motors round means it's ok, I'd guess. So if still not charging likely the control box. Is the cut-out relay part of the box making when you rev the engine?

I'll have the adjustment procedure for a Lucas regulator in an old BMC manual somewhere - I could copy that if needed.

Semi Hemi · Post by **Semi Hemi** » Wed May 11, 2011 8:14 pm

DaveEFI wrote:
Semi Hemi wrote:yes i've seen them altenator in a dynamo things and at around £400 ill give them a miss,well ive wired the D and the F on the dynamo together and it works like a motor so in guessing its the control box??
That will have polarised dynamo if needed. And if it motors round means it's ok, I'd guess. So if still not charging likely the control box. Is the cut-out relay part of the box making when you rev the engine?

I'll have the adjustment procedure for a Lucas regulator in an old BMC manual somewhere - I could copy that if needed.

im not sure what you mean about the cut out relay making?in fact im not sure abut the box at all i know if you take the cover off there are two coils with contacts on them,not sure what does what tho.
thanks for the replies.
kev