Ford dynamo

Richard Farrant · #1 13-11-07, 10:26

I am seeking info on a Ford dynamo fitted to a V8. It is one British engine fitted to a Fordson WOT, normally a Lucas item and I am not fmiliar with the Ford one and cannot find anything on them. My question is, which are the correct terminals, in relation to the attached photo. The wiring was not connected so I want to get it correct first time as it is being rewired.

From the CAV control board, there are the two wires, F (Field) and D+ (Dynamo positive). The dynamo has a cap on top with terminal at pulley end and brush end, I need to know which is which.

Tony Smith · #2 13-11-07, 11:54

Richard, Brad had a similar question in THIS THREAD. That style of Generator with the Cutout on top is an earlier style to that fitted to CMP's, but the same as on Universal Carriers. I wonder if he ever got that answered?

Richard Farrant · #3 13-11-07, 21:10

Tony,

Thanks for your response and the link to a previous query on the subject. Not sure this is of help to me though.

I was not aware that this was an old third brush type dynamo, I have seen a similar one in the wksp manual for a Canadian Mk1* carrier, but it had a box attached to the brush band and I assumed that was a third brush control box, and the one here was a later type.

The odd thing was that this was wired in to the vehicle prior to removing the engine, not sure if it was charging, and someone else removed the wiring, without checking the connections. It has just dawned on me, that this dynamo would be unlikely to be 12 volt, the WOT models were 12v, so must have been substituted in its later life. Looks like I am in need of a 12volt Lucas dynamo then

Lynn Eades · #4 13-11-07, 21:44

The voltage is controlled by the position of the 3rd brush.
(A common old c39/ c40 Lucas gennie is good for 50 volts, but is controlled by the regulator) (Im not saying it will handle 50 volts for long. It will burn out)Your 3 brush gennie should handle 12 volts. (gut feeling only)
The box attached may have been for radio suppression.

Richard Farrant · #5 13-11-07, 22:07

Quote:

Originally posted by Lynn Eades
(A common old c39/ c40 Lucas gennie is good for 50 volts, but is controlled by the regulator) (Im not saying it will handle 50 volts for long. It will burn out)Your 3 brush gennie should handle 12 volts. (gut feeling only)

Thanks, Lynn, that is reassuring. Now, any idea which terminal is which, to match up with my CAV regulator box (as in my first post ) ?

Lynn Eades · #6 14-11-07, 05:53

O.K. Richard, I dont know much about these three brush generators (dynamo)but I very much doubt that its 12volt.
The more I read the less I think that you can get 12volts out of it.
If you run it, and its not hooked up, it will burn out.
I suggest you find a Lucas unit. The main thing is the mount (drive end bracket) To convert a C39 or C40 from 6 to 12 volts requires the appropriate field coils. The 6 volt armature will work for 12 volt, but the 12volt armature is not up to the job for 6 volts.
Another option is to graft an alternator in if your not too concerned about it looking original. If you go the alt. way, you will probably need a small dia pulley on the alternator.

Hendrik van Oorspronk · #7 14-11-07, 07:45

Hello Richard, can you help me with the castingnumber on your cylinderheads and are they 21 or 24 studs? I think in my carrier is a Fordson engine as I nowere on the net can find the numbers, on my heads 77E6050A

Green Greetings

Hendrik

Ian Pullen · #8 14-11-07, 08:12

Guys, were getting in too deep here. Remember, it's a Lucas Dynamo. It doesn't matter which terminal you hook it up to. It either won't work or it will burst into flames!!

T Creighton · #9 14-11-07, 08:23

Hello Richard,
I have scanned a page from an ancient Dykes Automobile Encyclopedia under Model A Ford wiring. The picture of the generator and cut out in this book looks the same as the one you have posted. Ford didn't change things much so it might apply in your case.
Hope it is of some use.
If you have a third brush current control there will be no regulator box (as in later models) only the cut out.
I once had a 1936 Chev car with third brush genny and an auto electrican converted it to a two brush system and fitted a current/ voltage regulator . Worked well and fixed all the flat battery problems
Cheers, T

Mike Kelly · #10 14-11-07, 11:27

My two pennies worth ....

Those 3 brush dynamos are self regulating to a large degree .. a small amount of voltage is tapped via the 3rd brush .. Unlike the more modern 2 brush design , there normally isn't any external voltage regulator involved , in the 3rd brush system , the regulating is done by the internal inductance/reactance characteristics of the thing. They often had a high/low charge rate which was swtitched in and out depending on /winter summer conditions etc.

Some people used to remove the 3rd brush and convert them to a 2 brush system with an external regulator ... that's not a good idea because : the 2 brush design has the full nominal output voltage across the field coils .. In the 3 brush setup , only a small amount of voltage appears across the field coils .. result of the conversion is the coils carry far more current than they were designed for and they eventually break down from over heating.

Richard , check that it isn't a bodgy conversion that somebody has done on that truck ...

Mike

Richard Farrant · #11 14-11-07, 20:20

Quote:

Originally posted by Ian Pullen
Guys, were getting in too deep here. Remember, it's a Lucas Dynamo. It doesn't matter which terminal you hook it up to. It either won't work or it will burst into flames!!

No, no Ian,

It is a FORD dynamo, ten times worse than a Lucas

Alex Blair (RIP) · #12 14-11-07, 20:38

Quote:

Originally posted by Richard Farrant
No, no Ian,

It is a FORD dynamo, ten times worse than a Lucas

Richard..
This link may help..
http://www.ytmag.com/cgi-bin/viewit....oard&th=612679

Richard Farrant · #13 14-11-07, 21:25

Quote:

Originally posted by Mike Kelly
Richard , check that it isn't a bodgy conversion that somebody has done on that truck ...

Mike,

You have hit the nail on the head here

This is a 12volt vehicle, British Fords were ahead here! I have rewired the truck as original, cleaned the CAV regulator (same as MCC, Bedford, etc). Wired everthing in except the frigging dynamo as I was not sure of the connections, I did not disconnect the old cables when taking the engine out. I assumed at first that this Ford dynamo was an optional fitment from the normal Lucas, then finding out on here that it is a third brush type and 6 volt, has made me realise the bodgers had been at it. The best solution is to get a "King of the Road", Lucas one as then it will be compatable with the CAV regulator. The previous owner only ran it briefly, but did not recollect seeing a charge, so it may already be rooted.

Many thanks for everyones input on this, I can see that it would have been possible to run the system in the old third bush mode, but after making up a harness to suit a regulator, it is not worth going in that direction.

Richard Farrant · #14 14-11-07, 21:34

Quote:

Originally posted by Hendrik van Oorspronk
Hello Richard, can you help me with the castingnumber on your cylinderheads and are they 21 or 24 studs? I think in my carrier is a Fordson engine as I nowere on the net can find the numbers, on my heads 77E6050A

Hi Hendrik,

Just checked the Fordson WOT parts list and the number you quote is correct for a British 21 stud engine ( same as one in truck I am working on).

lynx42 · #15 14-11-07, 23:04

G'day Richard,

My Ford Lynx has a 12V geny from new. It's interesting that the engine runs the 4 1/2V coil and 6V starter, but the lights etc are 12V. This is the set-up for running the radio.
So Ford 12V generators are out there from 1943 on.
Regards Rick

Hendrik van Oorspronk · #16 14-11-07, 23:20

Quote:

Originally posted by Richard Farrant
Hi Hendrik,

Just checked the Fordson WOT parts list and the number you quote is correct for a British 21 stud engine ( same as one in truck I am working on).

Thank You, now I know why I couldn't keep up with the other carrier at operation Forrard On, I missed at least 10 HP

Green Greetings

Hendrik

Richard Farrant · #17 15-11-07, 00:00

Quote:

Originally posted by lynx42
G'day Richard,

My Ford Lynx has a 12V geny from new.

So Ford 12V generators are out there from 1943 on.

Hello Rick,

Ah, thats interesting, so perhaps this one is a 12v, could not see any numbers on it, but will look again.

lynx42 · #18 15-11-07, 08:57

G'day again Richard'
Just went and had a look at the Lynx generator. Different to yours in that it's a 2 brush geny with a regulator mounted on a removable band. The only stampings are:-

12V
C
1 X

and FIELD for the correct wire placement.
No cover band over the brush area and 4 narrow slots about 2 1/2 inches x 3/8inch around the circumference

I'll be away for a few days at the Bendigo SwapMeet, so on my return I'll take a photo for you if you want it.
Regards Rick.

Lynn Eades · #19 15-11-07, 10:41

Wiring changes are minimal.

Richard Farrant · #20 15-11-07, 19:35

Quote:

Originally posted by Lynn Eades
Wiring changes are minimal.

Thanks Lynn,

I can see it is simpler, but it would be a rather backward step. Anyway, the next job is to check the output from this dynamo, may not be any good, then it will be replaced by the correct one.

Much appreciated everyones help on this

Lynn Eades · #21 16-11-07, 05:42

I dont know where you are at with this. I cant answer your original question, BUT!!!
One side of the cut out has two wires, the other has one.
One side has a light wire that comes from the switchable side of the ign. sw., goes through the ign. warning light and away to the cut out, and connects on the same side as the heavy wire coming out of the dynamo. The single wire on the otherside of the cutout is wired into the permanent live feed from the solenoid.
I'm pretty hazy on this bit about how it works, but here is something to think about.
The small current flowing through the ign. warning light is the power to excite the field coils to start the generator. when the voltage rises up to say 6.8 volts, the cut out will start to vibrate open and closed, and thus regulating the out put.
If you take the top off of the cut out you should be able to work out how it works.
Remember with these fine British systems, it is the opposing voltage from the other end that puts out the ign. light.
I hope this helps