Hi all. I have a positive ground alternator sitting on my shelf. What do I need to do to put this on my '61 Mk2 2.4 that still has the generator?
Thanks,
Walter

 

It is a fairly straight swap. You will just have to make a new bracket to hold the alternator if the original bracket does not fit.
The RB340 voltage regulator will be removed and the wiring altered. I did this conversion from Generator to Alternator on my S Type several years ago and wrote a thread about it on the Jaguar S Type forum. It lists all the connections to the RB340 and which ones you need to discard and others you keep. You can find that thread here. Converting to an Alternator and Negative earth - THE INTERNATIONAL JAGUAR 'S'-TYPE REGISTER FORUM
If this link does not work let me know and I will cut and paste the relevant details on to this thread.

 

Thanks Cass. The link works. I will take a look at the thread when I'm ready to make the swap. Right now, I'm still sorting out other issues with the car. Mainly setting up ignition components and carbs.
Thanks.
Walter

 

Cass,
I was looking at your post and the instructions from Dynalite, and it is that simple, at least I think so, with the exception of the Ammeter.
That exception is that the connections to it have to be reversed when converting the car from POSITIVE to NEGATIVE ground.

No need to run new wires (if you did), why not just connect the wires together at the regulator box ?
Just disconnect the BATTERY and FIELD wires at the regulator and connect them together; this would accomplish the large wire from the Dynalite alternator being connected to the ammeter and hence the correct side of the ignition switch.
This is marked in BLUE.
This would be the thick wire.

The wire for the warning light is even simpler, it's already connected to the light on the correct side, it just has to be changed over to the Dynalite when it's installed.
It does not need to be connected to the regulator anymore.
This is marked in RED.
This would be the tin wire.

Connecting things this way allows one to use the present wiring that's there.

For originality, the regulator could be gutted and the connections "B" (battery) and "F" (field) could be made internally.
The same for "D" (dynamo), but that one is even easier as the connection is already made to the warning light _ it would remain plugged into the regulator for "looks" only, but it is important that any internal connections would need to be disconnected.

If one did not want to leave the regulator in place, a double ended male spade connector would be needed so B and F; "Blue" in my diagram, could be connected outside the regulator box.
No need to worry about colour codes here if one just pays attention to the marking on the regulator box. B, F, and D

Steps 1 through 8 has to followed of course.

 

Jeff I covered the Amp meter at point 5 where I stated the wires had to be swapped or the reading would show charging when in fact it would be discharging. I did not have to use any new wire as the original connections from the ignition light to the RB340 reached the Dynalite as did the original battery wire. Having said that the Battery wire is going to be taking more current so it might be best to check the integrity of that wire as old wiring does have a tendency to get hot and over hot is not good.
I had thought of putting the RB340 black box back on the inner wing as a dummy but ended up using that space for an brass radiator expansion tank modification instead.