TR2/3/3A Two black wires on control box E where do they g0 after alternator conversion?

[Momikey]

I did alternator conversion on tr3a the two black wires hooked to the E terminal the small wire sparks and smokes when hooked to alternator wires where does it go to?

 

[mgedit]

The E terminal is Earth or Ground. Here is how mine is wired after I did the alternator conversion and gutted the control box (which was not working anyway).

Cheers, Mike

 

[Momikey]

The E terminal is Earth or Ground. Here is how mine is wired after I did the alternator conversion and gutted the control box (which was not working anyway).

Cheers, Mike

View attachment 43780

So should I just keep the two ground wires on the box to keep them ground?

 

[mgedit]

That is how I have mine wired ... the two black ground wires just stayed in the same place on the control box.

Not sure what wire you mean when you say "the small wire sparks and smokes when hooked to alternator wires where does it go to?" You mean the small black wire when connected to some other wire other than black?

Is your wiring stock or has it been modified? The black wires should be ground if nothing has been modified.

Cheers, Mike

 

[dklawson]

I am confused by the wiring shown in the pictures above. It appears to show all the terminals are joined together. Is that what was intended?

The pinout of the TR3 control box will be the same as that used on the Mini and many other cars of the period. The articles linked below discuss how to alter the wiring to the control box AND how to gut a control box and use it as a junction box so you don't have to cut any of the original wiring harness.

Alternator conversion wiring:
https://www.minimania.com/HOW__TO_CONVERT_FROM__GENERATOR_TO__ALTERNATOR

Control box conversion to junction box:
https://www.minimania.com/Changing_from_Dynamo_to_Alternator_721

 

[mgedit]

A1, A, and D are joined inside modified control box. Cheers, Mike

 

[Momikey]

That is how I have mine wired ... the two black ground wires just stayed in the same place on the control box.

Not sure what wire you mean when you say "the small wire sparks and smokes when hooked to alternator wires where does it go to?" You mean the small black wire when connected to some other wire other than black?

Is your wiring stock or has it been modified? The black wires should be ground if nothing has been modified.

Cheers, Mike

The wiring instructions and the video on the moss web site say to remove all wires from the control box and connect the small wire from alternator to indicator light wire from box and all the other wires connect to the big wire from the alternator. So we did this and the ground wire started to smoke when we reconnected the battery so we un did the two ground wires and left everything else and it was working but my ground wires are not hooked to anything right now.
So I will put the two ground wires back on the control box were they were.
Now there is also the one ground wire hooked on the side of my box witch I see grounded to the body on some cars I assume that just stays there as well?

 

[dklawson]

... So we did this and the ground wire started to smoke when we reconnected the battery so we un did the two ground wires and left everything else and it was working but my ground wires are not hooked to anything right now.
So I will put the two ground wires back on the control box were they were.

Per other replies above and the links I posted, when you convert a control box to be a junction box during the change to an alternator, the black wires are not used. Remove them and tape up their terminals like you did earlier. Do not connect the black wires to anything.

 

[Momikey]

Per other replies above and the links I posted, when you convert a control box to be a junction box during the change to an alternator, the black wires are not used. Remove them and tape up their terminals like you did earlier. Do not connect the black wires to anything.

Is that because the Alternator is grounded to the car all ready.
Also I did not re use the control box I just un did the wires from the box and hooked directly to the alternator wires as per the instructions.
If I just leave the ground wires on the box does it make a difference?

 

[dklawson]

The old control box has no function when an alternator is installed. The alternator has internal electronics that handle that function. The instructions I posted a link to appear to be different from the ones you used.

Succinctly, when an alternator replaces an generator, the wires on the generator control box are removed. The "large" wires are joined to each other and the small wires (EXCLUDING the black ground wires) are joined together. At the alternator, the old, large generator wire is connected to one of the large terminals on the alternator. The generator's small field wire is then connected to the alternator's small terminal for the charge warning light. Some take an additional step and run an additional heavy gauge wire from the alternator's remaining "large" terminal to the battery (+) terminal or the "hot" terminal on the starter solenoid.

Gutting a control box to achieve the alternator conversion is nice because you do not have to modify the wiring harness.