Fordson super major

[major92]

Hi Guys,

I'm Maarten from Holland.

We are rebuilding a fordson super major.
Now we have a problem with te gauges.

Our fordson is one with the 2 gauges near the steering wheel.
The problem is something with the oil pressure control light, and something with the loading control light.

Now, the oil pressure switch wire is connected with ground. Positive.

For example:

The holder of the oil control light has 2 wires. One from the switch, in the middle of the holder.
On the outside of the holder is another wire, also connected with the outside of the light holder from the loading control light.

So i think that the outside from the oil pressure holder must be negatave: the light will turn on.
When the oil pressure switch disconnect the positive switch, the light will turn off.

When we fit the gauges and the housing on the tractor, then the housing will be positive ( earth).
But what i thought: the outside of the lamp holder has to be negative...
The lamp holder, in the gauge, on the housing, makes metal on metal contact.
When that is negative, and the earth is positive....smoke and more horrible stuff....

If anything is not clear, juist ask and i will answer in my best english
Must i isolate the lampholder? I dont think so..?
Anybody an idea?

by the way, i think that we need this wiring diagram:

[Dandy Dave]

The oil pressure indicator grounds though the sending unit to complete the circut. If you are running positive earth polarity with the battery, the light will be hooked in the system to the negative side of the system. The elecrical flow will be complete with the tractor Not Running and the light will be on. with the tractor running, the light will be out. Same with Dynamo/Generator light. It will only be lit when the tractor is off and not running with the key on.

[Pavel]

It would seem that your bulb holders are ones designed for mounting on wood or plastic panels whereby the body is insulated from the battery. You either need to insulate them from the metal panel they are mounted onto [difficult, I would say] or replace them with bulb holders that have 2 centre contacts that are not in contact with the metal bulb holder body.

Pavel

[major92]

first to you both, thanks for your answers!

@ dandy dave,

I know how the oil pressure light works.
The problem now is that we have with not running engine, twice positive wires. One from the earth (switch), and another one which is connected to the oudside from the gen light.

Gen light works fine (i think), maybe not with running engine...thats for later.
First now, we want 2 lights tunrned on, with not running engine.

@pavel

I can isolate them, but that's not original {i think.)
Now we have 2 light holders like this:



Do you, or anybody know... are these metal lamp holders original for the dashboard?
Or maybe we need some other lamp holders {isolated?)
Maybe it's original that the hole gauge dashboard is isolated from the earth?

The question is: How is it original, made by Fordson? Can't find some pictures on the internet...
I hope that anybody knows it!

[peter2]

Hi,

these bulb holders must be isolated. I took a lot photos while restoring, but unfortunately not from the dashboard. If you look on ebay you see long and short versions. I used the short ones.
I can take a photo from one (bought too much), if I don't forget it, when I'm back in the workshop.

I got it from my Mini Parts Dealer, here's a photo: http://www.minispares.com/product/Class ... 20shop#mwp

Peter

[Pavel]

The wire connections of the bulb holders you have shown must be, and most likely are, isolated from the top metal part. This is because the panel they, the holders, are mounted into is connected via the tinwork and chassis rails to battery earth/ground. Check this out with a multi-meter set on resistance/ohms.
Those early wiring diagrams are a little difficult to follow, but the wiring sequence is:-
Y/R = starter motor to ignition switch.
B/G = ign. switch to oil warning light.
V = oil warning light to oil pressure sender unit in block.
Bl/B = connected to B/G above and goes to generator light. [also coupled with Y/G to horn switch]
Y/W = generator light to generator.
There appears to be nothing unusual with the bulb holders you have shown -- so it must be the wiring set-up that is wrong. I suggest you check this out first.

Pavel

[major92]

hi guys,

this is how the situation is right now.



the black/blue wire is always connected with the outside of the lamp holder, so it must be negative.
the best solution of the problem is buy some new wires and lamp holders?

then I have to call the nearest mini dealer in the neighbour, i think,

thanks for your help again!

[Dandy Dave]

Do not confuse Negative with Earth/Ground. Earth/ground can be either Positive or Negative depending on the polarity of your battery. If the battery is in the correct Positve Earth/ Ground in your Fordson Major the black wire, and Blue wire will all be on the NEG side of the Battery. The Yellow/Greene stripe wire feeds the horn switch.These bulb holders, unless they are defective, should be insulated from the outer steel housing. Easily checked with a Multimeter. If memory serves me right, The purple wire will go to the the oil pressure sending unit, and the yellow to the regulator at the "A" post. where "A" = Armature. The lights are fed from the Ignition switch with the blue wire. Colors sometimes change in the wiring harness where the connectors are in the middle. This is where you have to hook up everything that is known, and see what colours are left over that are hot when the key switch is in run position. If I was only there I could sort this for you in minutes with a multi meter. The swim is a bit far, and the water patrol would most likely pick me up and send me to the nut house for attemting it. Dandy Dave!

[major92]

Do not confuse Negative with Earth/Ground. Earth/ground can be either Positive or Negative depending on the polarity of your battery. If the battery is in the correct Positve Earth/ Ground in your Fordson Major the black wire, and Blue wire will all be on the NEG side of the Battery. The Yellow/Greene stripe wire feeds the horn switch.These bulb holders, unless they are defective, should be insulated from the outer steel housing. Easily checked with a Multimeter. If memory serves me right, The purple wire will go to the the oil pressure sending unit, and the yellow to the regulator at the "A" post. where "A" = Armature. The lights are fed from the Ignition switch with the blue wire. Colors sometimes change in the wiring harness where the connectors are in the middle. This is where you have to hook up everything that is known, and see what colours are left over that are hot when the key switch is in run position. If I was only there I could sort this for you in minutes with a multi meter. The swim is a bit far, and the water patrol would most likely pick me up and send me to the nut house for attemting it. Dandy Dave!

Yeah right.
The nut house? Don't think so, this helps me a lot.

Ground (earth) is positive, what is original.

Conclusion of the story is now: insulate the lamp holders, or buy some with a hard-plastic housing (already insulated).
How do other Fordson guys that? Just some skotch tape around the lamp holders?

[Dandy Dave]

They should already be insulated/ isolated with the bulb. Do a continuity test from the steel housing to all wires. You Should NOT have continuity. If you do there is a problem. They say that genuis and crazy's walk a fine line. Depends which side of the fence you fall off of. Dandy Dave!

[major92]

If the battery is in the correct Positve Earth/ Ground in your Fordson Major the black wire, and Blue wire will all be on the NEG side of the Battery.

Right. So, the the outside of the bulb holders are now negative.
Because the oil sender gives a positive signal trough the purple wire, also the dynamo gives signal trough the Y/W wire.

Now both lamps will turn on, I think.

Problem:
The outside of the bulb holder is negative. Inside positive. When we put the holder into the dashboard, (steel on steel), then we have a cut short. Outside bulb holder negative, makes contact with the dashboard > ground, positive...

My english is not very well, maybe I did'nt read good enough...
Any answer in quiet simlply English is very welcome

[Dandy Dave]

But the outside housings should be separate and not hooked to any of the 4 wires. If you are getting power though them to the housing, then they are incorrect. If you take the bulb out you should see a plastic insert or similar so that the holders do not conduct any current. It would be my guess that you have defective holders. Dandy Dave!

[major92]

I read this topic again ( slowly )...
and i also found this photo on the forum



Peter was right i think, we need insulated holders.

One thing I don't understand.
When we started to build the whole tractor off, for painting and some other rebuilding activities, the non-insulated holders were fitted into the gauges. (the oil and dynamo warning lights.)

Can't imagine that they have worked. They look like to me, that they were the originals... fitted by factory.
The only way that they have ever worked, can be that the dashboard was insulated in stead of the ground (earth).

Strange story, i think

[Pavel]

I think we have a small problem with communication here. But to cut a long drama short, check the following:
Both the bulb holders in your pic of them resting on the fuel tank are single contact ones, and these will not work in your Fordson metal panel -- especially as they are a clip-in fitment.
You need 2 contacts inside the bulb holder[s]. The the wiring to these 2 contacts are insulated from, and not connected to, the outer casing -- no matter how many wires come out of the bottom of it [but see below]. In fact, if you refer to the wiring diagram above you will see that both the ignition/generator and the oil lamps have 3 wires connected to them, with the 3rd, bridging wire, being black with a blue tracer -- and this provides the current from the ignition switch between both of them. But again, none of them are connected to the lamp body. And the wiring is very simple -- ignition switch to one holder contact; the other contact to either generator or oil switch depending which one you are wiring up.
As an aside, you can get after-market double contact ones that are 'universal' holders, and these have another wire connected directly to the SIDE of the lamp body which can be connected so as to provide light to a gauge such as an ammeter.

Pavel

[Jimcdbts]

Hi
The quality of some of the wiring looms is terrible, I have just wired up my power major and had the same trouble, i made my fordson negative earth as i have an electronic regulator fitted in the body of the original ,this boosts the output of the dynamo at slow speed and gives better charging. What i found was that the inside of the bulb holders at the dash had very bad insulators on the center pin for the bulb and when bulbs were fitted the pin actually touched the housing inside and shorted out resulting in smoke and nearly burnt wires, got another 2 looms the same before i modified the holder with better insulator inside.
Jim

[major92]

Guys,

Indeed. Miscommunication.
I thought that the outside of the holder needs power, anyway, but negative or positive...?? I didn't understand it....

Normally in electronics i know: outside holder is ground, and the wire in the centre is connected with the the switch or other kind of signals...


In this case, we have the holder, and in this holder are 2 connections.
These two connections are insulated from the outside of the holder, and ofcourse insulated from eich other.

Am i right now?
Now i understand how to check with a multi meter and ohms and that stuff...

Thank you all for your patience, think i got it now!

[Pavel]

Good! you've got it.
In this case polarity doesn't matter -- and it will only matter in the future if you decide to change your dynamo/generator for an alternator or fit any other modern electronic device.
Nothing succeeds like success!

Pavel

[major92]

right.

tomorrow I will check the holders with my multi meter.
For now: thank you

[Dandy Dave]

Yup, If you do not tell the bulb which polarity it is using, It will not mind at all. But the shorted insulators on the other hand, hate it either way. Dandy Dave!

[major92]

now, I did some tests, and hell yeah...
the outside was connected with the inside... not good.

why do stores sell this kind of shit....
worthless.

now we are looking for some GOOD stuff...
thank you again.

[Dandy Dave]

Digging though my sash of stuff I found this harness today. It took two to get it right for my Power Major. Some of it is like the FMD, It has been a while, but I think voltage regulator was like the older units. Some of it is like the Super. Here are photos that clearly show the correct sockets are plastic with separate rings that go into the housing. Single bulb, but the holders are insulated from the housing ring. The two with the yellow/red wire to the rear are to illuminate the units at night with the lights on. Those are grounded though the holder. Dandy Dave!