lights wiring help

ive diagnosed myself into a corner, while brush hogging at night, [ the only time i have] my jubilee shorted its lights out about 10;30 pm, , after finding my way out of the field in full dark! i found that even though i had a fuse in the power wire, [ these are added on lights, the jube never had factory lights] it had shorted out the whole mess, grounded power wire, but it didnt blow the fuse, impossible i thought, also the alternator [ 3 wire] went bad, but that may have been out when i started, anyway, went to diagnose, power to the switch thru the fuse, no power from the switch, i replaced the switch [ heavy duty toggle switch] power to the light now, but doesnt work, check ground, ground good, direct to bare tractor cast rear end housing, still no light, remove light from the fender, direct wire to battery and it works just fine WHT!? what am i missing, new alternator will not turn off the 194 litebulb either, but it may be because the battery is fully charged, the lights would put a load on the alternator if they worked, i just dont want the tractor to die out in the field with a dead battery and leave me walking in the dark, i want to be sure it all works before i go back out in there at night

What caused the short? Did you use a multi meter to check things? WIth the 194 bulb I'm guessing that it's an idiot lite? If so sounds like the alternator isn't working. WIth the short problem stating this I'd start with pulling the alternator and having it bench tested. If it's good then you are looking at a short in the wiring system. If you can build your own wiring harness it make be faster than trying to trace the problem.

Rick

If you have power at the light when the switch is on now, and the light works when you connect it direct, then it HAS to be a ground problem.

Try taking a length of wire and running it from the ground on the light back to the ground post on the battery. If it works, it is a ground problem.

You may have a general ground problem if the new alternator doesn't charge or turn off the tel-lite.

the 194 bulb is used in the circut to make the alternator shut off when the engine is shut down, much the same way the idiot lite does in a car, otherwise the circut will remain open and eventually drain the battery there has to be a slight load, on the system to make it disconect,[ over on the N board there is a diagram for this system, this simple wiring will allow the use of a 70's or early 80's gm alternator to be used on virtualy anything it can be mounted on , there cheap lol] the alternator is brand new as of yesterday and the wiring was working fine, i know this will be something simple and stupid and im overlooking it,

(quoted from post at 06:49:14 05/18/12) the 194 bulb is used in the circut to make the alternator shut off when the engine is shut down, much the same way the idiot lite does in a car, otherwise the circut will remain open and eventually drain the battery there has to be a slight load, on the system to make it disconect,[ over on the N board there is a diagram for this system, this simple wiring will allow the use of a 70's or early 80's gm alternator to be used on virtualy anything it can be mounted on , there cheap lol] the alternator is brand new as of yesterday and the wiring was working fine, i know this will be something simple and stupid and im overlooking it,

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AH OK I do my 12 volt conversions with a diode in line, not the light bulb.

But to my understanding the light should come one when the switch is moved to the run position and then go out like an idiot light once the engine is running and the alternator charging. I do agree that if you have power to the lights and they are not working but would when a drirect connection is made that you have a ground problem. As far as the 194 light staying on when the tractor is running, if my prior statement is correct then you got a defective alternator or you fried something when you shorted out the rear lights and now also have a wiring harness issue. Burning up the old alternator when you shorted the lights is a good indication that you did something besides just taking out the lights.

Rick

Not to be a smart alec, but I'm wondering about your use of the term "shorted".

I worked in a radio-TV shop for 20 years and usually when a customer called in for service their common analysis of the problem was "I think it's got a short in it"

A "short circuit" is the presence of a conducting path where it should not be. An "open circuit" is a break in a path that should be conducting.

If your lights "short circuited" there should be a blown fuse or a burned wire. So I'm wondering if proper term would be "open circuit" which could be bad ground as others have suggesteed

The on-off switch supplies voltage to #1 pin on common Delco alternator. Other end grounds through alternator causing the light to glow. What alternator kicks on it supplies voltage to the alternator side of the light and with equal voltage on both sides of the light it goes out
indicating that it is charging.

I have an 8N with rear light that did not work. Problem was rust and corrosion causing bad connection between fender and axle

I went through similar problem, got fed up, decided to put an end to it. I finally drilled a small hole in each light housing, ran a green ground wire in, the hose-clamped the copper wire dirctly to each light socket, with a very small hose clamp. Ran the green wires out and directly down to the battery, bolted the wire to the negative terminal, and the lights are as bright as can be.

Whoa, you got that somewhat hind end around backwards.
Exite current feeding the #1 terminal comes from the switched side of the ignition switch, same place the coil gets its current to generate spark. Turning the key to "off" cuts this feed. However, once the alternator starts charging there is a slight backfeed from the alternator to this wire. If there is no resisance such as the #194 bulb in the wire, it will feed the coil input. Hence turning off the key won't stop the engine. The resistance cuts the backfeed voltage enough that the coil won't fire.
It doesn't take much to exite the alternator. In the old days running service truck, sometimes the car battery was so dead that the 800 amp starting unit wouldn't jump start it. A 1.5 volt AA flashlight battery between the jumper clamps was enough to get things going.
Willie

lol "shorted", in this case was the 3 point lift arms came down, crushed the wires between them and the top of the axle tube, causing it to have a direct short to ground, bare hot wire to bare iron, about as direct a short as possible, lol

ok got it, lol , well, as grandpa used to say "dont pay attention to what i said, pay attention what i meant" lol i knew the 194 bulb had to be in that wire, lol i got that part right

thanks guys i didnt get to work on the tractor today had a 15 hour day at work, but tommorrow after i get back with a truckload of blocks, im going to run a whole new ground wire and see what happens let you know, also intrested in the new alternator, the 194 bulb always worked just like a idiot lite in a car, now the one time i fired the tractor up it stayed on, i didnt change any wires to the alternator, something tells me this aint over yet...

just letting all of you know on this problem i decided to quit fooling with it and rewired the whole tractor yesterday plus added a new carb that arrived yesterday , it now runs, charges, and lites up just like it should, thanks for all the help guys