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dynamo to Dynamotor conversion - help needed please!

PostPosted: Tue May 10, 2022 5:22 pm
by NickWilmshurst
Hello,

I decided to upgrade the old Lucas C40 dynamo to a Dynamotor which is sold by Accuspark here in the UK and is an alternator in a dynamo case. Here's the link if your not familiar with it... https://www.accuspark.co.uk/dynamator.htm

I followed the wiring diagram to the letter - my car is a series 3 with negative earth and has the standard wiring...
terminal A1 brown/blue to light switch and ignition switch
terminal A brown to solenoid
terminal F brown/green to dynamo (large terminal)
terminal D brown/yellow to ignition warning light and dynamo (small terminal)

The instructions are here (I have a RB106 control box) ... https://www.accuspark.co.uk/Instruction ... ctions.pdf

The way I read these instructions is that the control box is now redundant (except for the earth which is going to do nothing anyway) and that all the four wires as above should be connected together.
So far so good, except...the ignition warning light comes on when the key isn't even turned and then goes out when its turned to the first "click". Something evidently wrong but I am such an electrics simpleton I could do with any ideas or suggestions please!

Many thanks

Nick

Re: dynamo to Dynamotor conversion - help needed please!

PostPosted: Tue May 10, 2022 8:23 pm
by Andy8421
Nick,

Firstly, a quick correction. Your existing wiring should have F on the control box connected to the small terminal on the dynamo (field winding). The D should be connected to the ignition warning light and the large connector on the dynamo (brushes).

In your new setup, have you connected the ignition warning light to the small terminal on the dynamator? Either directly or via the existing brown/green wire ?

Re: dynamo to Dynamotor conversion - help needed please!

PostPosted: Wed May 11, 2022 9:52 am
by NickWilmshurst
Hi Andy,

Thanks for your reply.
My mistake, the brown/green wire goes from terminal F to the small terminal on the old dynamo.

In the new setup all the wires from the old control box (including brown/yellow) are joined together - so, yes, ignition warning lamp is indirectly connected to the small (F) Dynamator terminal.

Is that right?

Nick

Re: dynamo to Dynamotor conversion - help needed please!

PostPosted: Wed May 11, 2022 9:57 am
by elanfan1
Suggest you email Accuspark

Re: dynamo to Dynamotor conversion - help needed please!

PostPosted: Wed May 11, 2022 12:19 pm
by Andy8421
NickWilmshurst wrote:Hi Andy,

Thanks for your reply.
My mistake, the brown/green wire goes from terminal F to the small terminal on the old dynamo.

In the new setup all the wires from the old control box (including brown/yellow) are joined together - so, yes, ignition warning lamp is indirectly connected to the small (F) Dynamator terminal.

Is that right?

Nick

Nick,

With all due respect to Accuspark, their diagram is rubbish.

The ignition warning light needs to be connected directly to the small terminal on the Dynamator. Nothing else should be connected to the small terminal on the Dynamotor or to the ignition warning light or to this circuit. You could do this by running a separate wire, or by using the existing brown/green cable that runs from the F connection on the control box.

To do this, you should plug the existing brown/green cable onto the small terminal on the Dynamator (it would have originally been plugged into the small terminal on the old dynamo), unplug this cable at the control box end from 'F', unplug the brown/yellow cable at the control box end that leads to the ignition warning light from D, and connect the two cables together, you should now be in business. Nothing else should connect to these cables.

You should connect the other cables together as the Accuspark diagram shows.

I would agree that that the diagram doesn't make this at all clear.

I am afraid it is possible that if you have connected everything together you may have fried something. Give my suggestion a try and see how you get on, but be prepared for some disappointment.

Andy.

Re: dynamo to Dynamotor conversion - help needed please!

PostPosted: Fri May 13, 2022 3:28 pm
by NickWilmshurst
Andy,

Thanks very much for your help - I made the changes today and it works a treat!

I wanted to retain the look, as far as possible, of the original so I stripped out the innards of an old control box and made a plate for inside to join terminals together.

Nick

Re: dynamo to Dynamotor conversion - help needed please!

PostPosted: Fri May 13, 2022 6:56 pm
by Billmack
All four do not get connected together. Read the instructions carefully and follow to the letter. No mystery there