The Fordson Tractor Pages Forum

Hi Guys, Can anyone point me in the right direction. I want to fit an alternator to my Super because i use her as a working tractor and at the moment im working late into the evening wrapping, I want to fit some working lights to the roll bar.

Can anyone help with what i need to do.

Many thanks
Steve

Hi Steve,

Depends on the type of alt. you gonna fit.

Choose one with internal regulator. On wire direct to the bat terminal on the starter and a wire to ground and it works. Please note all alternators are negative ground.

Other solution is fitting a 22 Amp generator and regulator from a 5000. This looks more original and you can re-use your original wiring.

Rgds

Emiel

Go to a wreckers, Steve, and get a Lucas or Bosch [Bosch for preference] alt. of about 45amps or above. As Emiel states, you only need 2 wires -- one rated at 50amps from the alt. to the batt. + [pos].You can use the existing one to the ignition switch. As he also says, get one that is internally regulated -- most from the mid 70s are.
However, you will have to remove the the dynamo regulator [control box] and re-connect some of its wires together to complete the necessary circuits. Not too long ago I posted how to do this. When I have time I'll look it up. Either that or I'll re-post it.
You will have some agro fitting it and lining the pulleys up, plus fitting an adjusting strap. Washers are good for shimming. And, of course, you'll need a new size fanbelt.

Pavel

You can also get a true 1 wire alternator, AC Delco.. I just put one on, was about $90 plus tax (70 amp I think). It comes with a v-belt pulley attached, is pretty easy to make a mount for and only has a single wire to the positive battery post, no need to run a switch wire etc, won't drain battery..

Few things to keep in mind when getting something..
Fordsons are + grounded so unless it's been converted to - grounded you'll fry an alternator (which use the housing as -)
Second, if you do go the alternator route, don't cheap out on a 20-40 amp version, those amps are listed at a higher RPM than your tractor will ever spin it. Most auto alternators use a crank drive pulley about the same as our Fordson's but will spend most of their life with the drive (crank) pulley running at 1800-2800 RPM, you're going to drive it with a crank speed of 800-1500 so expect about 1/2 the amperage quoted at best..

Whilst Greg makes an AC Delco one wire self exciting alternator sound attractively simple, I would urge caution.
Firstly, I suspect that the single wire SI and CS models are a little thin on the ground in the Uk.
Secondly, the SI model has to be run at a crankshaft speed of 3,000 rpm before it will "leak" its regulator voltage to produce a charge. The CS model, often fitted to trucks [lorries] needs 1,000 rpm. One could, of course, fit a smaller alternator pulley to overcome the higher revs required.
On the other hand, a cheap as chips Lucas 17ACR [fitted to BMC, British Leyland, Rover,Triumph, Hillman & Singer etc. cars in the 70s & 80s] produces 36amps and 14volts. Even at half its rated output that's 234 watts. Using two 55w headlight bulbs, two 5w rearlamps and a single 100watt plough lamp, there is still a spare 24watts for a radio. Remember also that even at idle this alternator will still produce 13.6 volts with the headlights on high beam.
This is the alternator I use on my FSM, with the above lights, after I up-rated my [older] car with a Bosch 65amp one. Both have not let me down over the last 5 years.

Pavel

Not true Pavel! Pretty well all the SI units will output 1/2 their rated amps at 1600rpm, and that 1600 is alternator RPM, -not- crank. With typical pulley sizes used that's somewhere between 500 and 800 rpm engine crank..

Feel free to include your source, here's mine.

Greg
http://www.delcoremy.com/documents/elec ... guide.aspx see page 11 for output.

Dead right, Greg, I stated that wrong -- it should have read alternator rpm.
I did note, though, in your site recommendation, that whilst the suggested Delco-Remy 10Ci single wire unit has a much higher maximum amperage output, at an engine idle speed of about 550 rpm [alternator 1600rpm] the output is listed as only 0.23 of an amp -- much lower than the Lucas I quoted -- which is indicative of the low speed charging characteristics encountered with single wire set-ups. The site that refers to single wire set-ups is: alternatorparts.com/what_is_a_self_exciting_alternator.htm
There is also another General Motors site that discusses this.

Steve, whichever alternator you eventually decide to use, provided it is internally regulated, you will need to dispense with the dynamo regulator box and do some wiring work. The post that this was covered is dated May 27 2012 under 'Correct wiring for an Alternator'.

Pavel

Thanks so much Pavel, I finished all my hay making this weekend so I can spend sometime on the old girl now. Do I need to change her from Pos Earth to Neg earth then??

Cheers
Steve

Indeed you do, Steve, indeed you do! Any alternator you fit will almost certainly be '-' [neg.] earth. You may possibly have to re-polarise the starter and if so do it with the alternator un-wired.

Pavel

A bit more info, Steve.
Starter does not need touching -- I was a bit concerned about the somewhat involved solenoid set-up so checked it out.
If you have an ammeter you will need to change over the wires on it.

Pavel

Brilliant thanks so much Pavel, Will let you know how I get on.