Dynamator for Lazarus

This article is about my success at installing a Dynamator alternator into Lazarus, my 1952 TD 10855.  Lazarus has been converted to a negative ground configuration as long as I've had him.  Being a retired EE, I'm just to much of an electronic'er to have it any other way.  I'll not be getting into the steps necessary to convert from a positive ground configuration to negative ground. 

A bit of background. If you follow the train from Alternators for Tcars you'll see how I got into the alternator world.  In the past month I ran into some problems with Lazarus' charging system that led me to believe that I had either a bad dynamo or battery, or both.  Three control boxes (voltage regulators) weren't solving the problem.  I decided to bite the bullet and try an alternator.  Abingdon Spares has recently begun carrying a line of U.K.-built alternators called Dynamators at a very reasonable price, ~$220US. For the past month I've been doing a lot of corresponding with Mort Resnicoff and Jim Northrup about Mort's problems with his Dynamator.  So I've picked up quite a bit info about them.  A bunch of Googling led me to suspect that the trick necessary to convert a negative ground TD from dynamo to Dynamator was to KISS (Keep It Simple Stupid).  I saw two approaches - one was the Stealth approach for an installation where the casual observer wouldn't see the difference.  That meant having to sacrifice a control box by gutting its contents.  The other approach was to simply apply a standard electrical wiring connection strip.  I had an old RB106/2 control box that had seen better days, so I started down that path. Here's what the Dynamator folks put into the package:


Notice that the 'With Dynamator' shows nothing connected to the RB106 except a ground wire on terminal E.  The control box must be totally eviscerated for this application.


The device in the empty control box is a 40 amp fuse. What does all of this accomplish? Here:

The wires attached to A1 and A of the control box are bussed together and the 40 amp fuse is connected to them.  The other end of the fuse is connected to the D terminal.  The small yellow wire from the Ignition Warning Light that was attached to the D terminal is now connected to the F terminal with the Field wire from the Dynamator.  The black (ground) wires remain connected to the E terminal.  I have connected the D terminal of the control unit to the D terminal of the Dynamator with a length of yellow,10 gauge wire.  Dynamator says -- Note: The wire used as main feed from Dynamator to Battery should be rated at at least 45 amps. IMHO, the short length of 10 gauge wire should satisfy that demand, but the decision is yours.  The yellow wire presently connecting the D terminals is designed to handle the 20 amps of the C39/C40 dynamo.  One might want to change the path of the D wire since the D terminal is a push-on terminal on the end of the Dynamator.


It's not mentioned in the instructions, but you'll need to swap the cooling fan from your dynamo to the Dynamator.  When I first ran my engine I could hear the ping-ping of the fan contacting the Dynamator housing.  I solved that by installing a thin spacing washer (26 ga. steel) below the fan. I think that the interference may have been due to the repro fan that I've had on the dynamo.  FYI, the 40 amp fuse and the 10 gauge wire are readily available at NAPA stores.


Next comes the directions for doing the conversion without the control box. Click here.



Who's Lazarus?

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