5 replies to this topic

[Minime998]

Hi,

 

Can anyone help me identify this alternator. I believe its a Dynalite, but I don't know if its a positive or negative earth. I recently bought it with the car/engine but isnt wired. There is no relay which is on the positive earth but it may have been removed. I have trawled through the pics for Dynalite alternators but cant confirm which it is:

 

 alt1.jpg   55.69K   1 downloads

 

 alt2.jpg   53.75K   1 downloads

 

The extra connector here makes me think it could be the positive earth.

 alt3.jpg   38.67K   1 downloads

 

 alt4.jpg   48.75K   1 downloads

 

The car is a Mk2 1968 cooper

 

thanks

Edited by Minime998, 15 September 2021 - 12:26 PM.

[MikeRotherham]

Does the item have a model number or serial number on it that you could give to the manufacturer to identify which it is?

Edited by MikeRotherham, 15 September 2021 - 12:45 PM.

[Minime998]

Thanks Mike, There were no markings. But after trawling through lots of pics of retro style alternators I have found it on SC parts (not Dynalite). I will contact them to see if there is an easy way of finding out. In either case I bought the 'RB106XB Powerlite Dummy Dynamo Voltage Regulator Control Box LUCAS RB106 Blade' I believe I can still use this looking at the fitting guide, can anyone confirm?

 

Thanks

[ace01]

In terms of ID, I think it could be this one.  https://www.carbuild...AEaAmGhEALw_wcB

 

As to whether it is pos or neg earth; If it was bought for the car it should be neg earth as positive earth had been phased out by then.  

 

Just because it has the extra terminal is by no means a guide.  Pos or neg would have the same connections.  An alternator or dynamo would have at least two connections.  One for the feed and one for the charging light on the dash.

[Minime998]

Thanks Ace, that looks like the one, so helpful cheers. Looking on the site, it looks like I can connect a multi meter, stick the + on the terminal and - on the body and spin clockwise if the voltage shows the correct polarity that should confirm? 

[Spider]

Thanks Ace, that looks like the one, so helpful cheers. Looking on the site, it looks like I can connect a multi meter, stick the + on the terminal and - on the body and spin clockwise if the voltage shows the correct polarity that should confirm? 

 

I was just reading through here and was about to suggest this but some caution is needed !

First, check your meter as to the polarity of the leads when on the Ohms Range. The Analogue Meters are usually reversed and the Digital Meters could be either way. Check first. You'll need a 2nd meter to check for this polarity, just check it by measuring for DC Volts.

Once the Meter Polarity is established, if you put the (true) -ve lead on the Charge Terminal and the +ve lead on the Body and get a low resistance reading, then it is Negative Earth. Check it the other way and it should show Open Circuit or a very high resistance.