The Fordson Tractor Pages Forum

Hi, I'm starting to pick my way into the electrics on this tractor so some questions to start with...
The key/ light switch needs replacing, which is better - metal or plastic?
The regulator - clean' test, reset, repair? Bin it, get a new one?
Are the headlights (currently missing) twin aspect ie dip/main?
Where should the horn (missing) be?
How much agro is it to the reverse the polarity to get neg earth? This machine will never be A1 original and is going to need a fairly complete rewire so if I'm going to get in that far then a neg earth system would be compatible at any later date for led bulbs, new type trailer boards, an alternator upgrade perhaps, and maybe a sneaky socket for a phone charger in the toolbox (also saves head scratching from the younger generation when jump starting!!!). I understand the dynamo can be flashed to switch the polarity, and swap the wires on the ammeter, but what is the procedure for the starter and regulator?
A basic test of the dynamo shows 20v so that's ok, but no increase in V at the battery although the ammeter twitches occasionally so the regulator needs work, and most of the spaghetti in the dash is very overcooked!
Your opinions, good or bad, are most welcome.

If there's one thing I can say it's leave everything as untouched as possible but fully functional. You'll then save yourself drawing a new wiring diagram.
Your switch should have the fixing holes in line with the centre and be a metal light switch knob and body.
Try seing what's wrong with the regulator, the Ford repair manual gives a good idea of what to do, but it seems to be a bit reluctant to connect.
The headlights are dual beam; make sure you use 35/35W bulbs to avoid draining the battery.
Here's the position of the horn (original one).

If you want to plug something in, use the std output socket and wire everything to it. (This is the early socket)

To connect anything like a modern trailer use an adaptor and rewire the earth on the trailer to isolate it; with std. bulbs the switch in polarity won't make any difference.
I thoroughly recommend having a big battery as well.
Sandy

Unfortunately there's a lot of already toasted wire in the dash that's unidentifiable so some replacement lines will need to go in, including a fused live feed to the key to hopefully stop it happening again, although I suspect the loose bare ended lighting wiring may have had a hand in it.
Thanks for the horn location, I was looking for a wire running towards the nosecone!
I won't be back with it for a few weeks now so some time to consider the options.
Thanks.

I thoroughly recommend looking at the original wiring diagram to see what is toasted. A loose end for the light wire is very likely to have caused this (as you were saying you have no lights). The fuse would need to be quite big.
Sandy

Doing some basic maths...
2x35w headlights = 70
2x5w combination side lights = 10
2x5w trailer lights = 10
1x3w oil light =3

So the max draw through the keyswitch feed is 93w call it 96, divide by 12 is 8 amps, then whatever the control box and starter primary coil uses and I would think 10-15A fuse would be sufficient. The chances of needing to start with all lights on is fairly remote. When I get back into working on it I'll do an ohms/V calculation on the starter primary so I have a benchmark to work with then once it's all up together I can make an actual measurement and fettle accordingly.

You will need to add the horn and another 5W bulb for the rear/number plate light. If you have extras in the socket you'll need to allow for more.
I don't know what you mean by oil light.
This would come to 95W plus socket extras.
Sandy