LED died after a few weeks.... WTF

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My 50+ year old farm tractor had no indicator lamp to indicate the
ignition power is on. There is no key, just a push-pull switch. There
is also no gas gauge, so I never know when it will run out of gas. It's
no big deal to run out of gas. I just need to make sure I keep a 5
gallon can on hand. The problem is that when it runs out of gas, I
often forget to shut off the ignition switch, and if that switch stays
on for a few hours, the battery is dead.

I went to Radio Shack and bought a LED "pilot light" (has a built in
resistor and an enclosure around it). It's made for 12 volt. (The
tractor has a 12v battery). I installed it, and it worked great.
Within a few weeks I noticed it would flicker, get dim, go back to
normal, and so on. Eventually is just died, after only a few weeks of
use. Yea, the wiring is fine. I intentionally chose a LED to avoid
changing burned out bulbs.

Why would a LED burn out so quickly?

I should mention that the tractor has an alternator from a modern car,
with built in regulator. These tractors originally had an old generator
with eternal regulator, and were 6 volts. Almost everyone who still
uses them have converted them to 12v, which is simply changing to a
modern alternator, getting a 12v starter, changing 2 headlight bulbs,
and putting a different resistor on the ignition coil. And of course
using a 12v car battery.

Maybe this is just the result of buying crap from Radio Shack....
But I wonder if the vibration of the tractor or something else caused
such a short life???

 

[Ecnerwal]

Maybe this is just the result of buying crap from Radio Shack....
But I wonder if the vibration of the tractor or something else caused
such a short life???

Water. Tractors don't tend to be dry. Cheap electronics from radio shack
don't tend to resist water. Or else your mouse (every tractor dashboard
has at least one, in my experience) likes the flavor of the wire - if
so, that will become obvious when you remove it.

 

[mike]

My 50+ year old farm tractor had no indicator lamp to indicate the
ignition power is on. There is no key, just a push-pull switch. There
is also no gas gauge, so I never know when it will run out of gas. It's
no big deal to run out of gas. I just need to make sure I keep a 5
gallon can on hand. The problem is that when it runs out of gas, I
often forget to shut off the ignition switch, and if that switch stays
on for a few hours, the battery is dead.

I went to Radio Shack and bought a LED "pilot light" (has a built in
resistor and an enclosure around it). It's made for 12 volt. (The
tractor has a 12v battery). I installed it, and it worked great.
Within a few weeks I noticed it would flicker, get dim, go back to
normal, and so on. Eventually is just died, after only a few weeks of
use. Yea, the wiring is fine. I intentionally chose a LED to avoid
changing burned out bulbs.

Why would a LED burn out so quickly?

I should mention that the tractor has an alternator from a modern car,
with built in regulator. These tractors originally had an old generator
with eternal regulator, and were 6 volts. Almost everyone who still
uses them have converted them to 12v, which is simply changing to a
modern alternator, getting a 12v starter, changing 2 headlight bulbs,
and putting a different resistor on the ignition coil. And of course
using a 12v car battery.

Maybe this is just the result of buying crap from Radio Shack....
But I wonder if the vibration of the tractor or something else caused
such a short life???

sometimes, stuff just fails.
Split the resistor in two and put a zener from the middle to ground.
Mount the led so that the leads can't move wrt the head under vibration.

 

[[email protected]]

What kind of Tractor? (I love my ~'49 T0-20 Fergeson.)
I like the water/ wildlife idea, maybe you can go to the local tractor
dealership and get an indicator lamp made for outdoor use.

A Farmall Super M. I like the Farmalls. I have an H too, but its
presently needing major repairs.

These Farmalls have a small box on the steering post for switches, a
fuse holder, and stuff like that. I put the LED in there. While I'm
sure a little moisture gets in there, it's pretty water tight, and mice
can not get inside. The external wiring is exposed and nothing chewed
on that. But I'll have to see what the dealership has, since this
didn't work.

I check all the fluid levels before starting the tractor, so I rarely
run out of gas. It's also got a fuel valve that you can open another
two turns and tap an extra gallon of gas in the bottom of the tank....
So you don't have a long walk to the back forty.

George H.

If I'm going out to the field, I do check the gas, but most of the time
I'm just running hay bales and other feed from the hayshed to the barns
and paddocks. 10 or more square bales get fed each and every day in all
climates and weather conditions. In good weather I might use the garden
tractor with cart, but most of the time the Farmall loader is the
fastest and easiest. Often the weather is crappy, so it's just toss the
bales on the loader and go. I usually dump in 5 gallons at a time, so I
sort of know about what day I'll run out, unless I do other chores with
the tractor in between. My gas can is normally within 300 feet when I'm
doing chores. The problem is that I may run out of gas just as I'm
finishing, and my last hay goes downhill, so I can coast down. I've
been known to toss a few bales on the hood of my car too if I'm in a
hurry and run out of gas. But at my age, I'm forgetful, and just never
seem to remember to shut off the switch when I run out of gas. When
that LED was working, I always saw it. Bright Yellow one!!!

Maybe I'm wrong, but it would seem to me that the dealerships would have
all incandescent bulb type indicator lights. I wanted LED to eliminate
replacing bulbs and even more to eliminate a power sucking incandescent
bulb. LEDs use almost nothing....

 

[Martin Brown]

My 50+ year old farm tractor had no indicator lamp to indicate the
ignition power is on. There is no key, just a push-pull switch. There

I went to Radio Shack and bought a LED "pilot light" (has a built in
resistor and an enclosure around it). It's made for 12 volt. (The
tractor has a 12v battery). I installed it, and it worked great.
Within a few weeks I noticed it would flicker, get dim, go back to
normal, and so on. Eventually is just died, after only a few weeks of
use. Yea, the wiring is fine. I intentionally chose a LED to avoid
changing burned out bulbs.

Why would a LED burn out so quickly?

Possibly because the alternator charging the battery has a fair bit more
than 12v across the terminals (maybe 16-17v peak). I am surprised that
it is enough to shorten the LED lifetime but with junk from RadioShack
anything is possible. Try again and be careful not to bend the leads
close to the LED plastic - that will kill them.

I should mention that the tractor has an alternator from a modern car,
with built in regulator. These tractors originally had an old generator
with eternal regulator, and were 6 volts. Almost everyone who still
uses them have converted them to 12v, which is simply changing to a
modern alternator, getting a 12v starter, changing 2 headlight bulbs,
and putting a different resistor on the ignition coil. And of course
using a 12v car battery.

Maybe this is just the result of buying crap from Radio Shack....
But I wonder if the vibration of the tractor or something else caused
such a short life???

I'd bet on mechanical handling whilst installing it.

 

[Jamie]

Possibly because the alternator charging the battery has a fair bit more
than 12v across the terminals (maybe 16-17v peak). I am surprised that
it is enough to shorten the LED lifetime but with junk from RadioShack
anything is possible. Try again and be careful not to bend the leads
close to the LED plastic - that will kill them.



I'd bet on mechanical handling whilst installing it.

my guess would be he has it connected to the solenoid circuit for the
fuel or ignition, either way, both the same. If no wheeling protect or
over voltage is employed, this little device will be short lived!

Of course, over current I(f) does not help either. And If memory
servers, direct sun light on the dome of the LED can play havoc. Being
farm equipment, it most likely is exposed to the sun a lot.

Jamie

 

[amdx]

I usually dump in 5 gallons at a time, so I

sort of know about what day I'll run out, unless I do other chores with
the tractor in between. My gas can is normally within 300 feet when I'm
doing chores. The problem is that I may run out of gas just as I'm
finishing,

Reminds me of when I was a kid, my dad had a "51" ford pickup with a
broken gas gauge. Every time he drove it, he would stop at a gas station
and put in $1.00 worth of gas.
I was with him one day and he couldn't get $1.00 worth in the tank.
It was full!
Mikek

 

[Martin Brown]

my guess would be he has it connected to the solenoid circuit for the
fuel or ignition, either way, both the same. If no wheeling protect or
over voltage is employed, this little device will be short lived!

Of course, over current I(f) does not help either. And If memory
servers, direct sun light on the dome of the LED can play havoc. Being
farm equipment, it most likely is exposed to the sun a lot.

Never known an indicator LED killed by solar exposure. The ancient ones
were too dim to see in strong sunlight but that is a different matter.

It crossed my mind after I had posted that the starter motor back emf
probably exceeds the reverse bias to kill an LED not protected by a
diode. Tractors are very harsh environments so the poor LED will require
a bit more protection than just a series resistor. Inductor in series
and diode in parallel should tame the electrical environment.

 

[[email protected]]

Possibly because the alternator charging the battery has a fair bit more
than 12v across the terminals (maybe 16-17v peak). I am surprised that
it is enough to shorten the LED lifetime but with junk from RadioShack
anything is possible. Try again and be careful not to bend the leads
close to the LED plastic - that will kill them.

I'd bet on mechanical handling whilst installing it.

This is NOT a bare LED. It's in a holder with insulated wires coming
out. All I did was drill home in tractor switch box, insert and tighten
the nut. Connected the ground wire to the frame, red lead to the wire
screw on the ignition switch. I made pigtails (since the LED wires were
short), put spade terminals on their ends to connect to the ign switch
and ground. Used very small wirenuts to connect the LED wires to the
pigtails. (I do have a ground wire from the battery terminal to this
control box to insure a good ground, since this tractor is old, there is
some rust where things are bolted, so this makes a good ground)

[The built in resistor is inside the light]

This is the exact light that I have. On the Radio Shack website. Orange
(looked yellow to me, but color was good when it worked).
http://www.radioshack.com/product/index.jsp?productId=2062570

 

[P E Schoen]

wrote in message

This is NOT a bare LED. It's in a holder with insulated wires
coming out. All I did was drill home in tractor switch box, insert
and tighten the nut. Connected the ground wire to the frame,
red lead to the wire screw on the ignition switch. I made pigtails
(since the LED wires were short), put spade terminals on their
ends to connect to the ign switch and ground. Used very small
wirenuts to connect the LED wires to the pigtails. (I do have a
ground wire from the battery terminal to this control box to insure
a good ground, since this tractor is old, there is some rust where
things are bolted, so this makes a good ground)

[The built in resistor is inside the light]

This is the exact light that I have. On the Radio Shack website.
Orange (looked yellow to me, but color was good when it worked).
http://www.radioshack.com/product/index.jsp?productId=2062570

You might look closely at the resistor inside the housing. It may not be
soldered properly or vibration may have caused it to break a lead on the
LED. It does not appear to be potted or secured in any way. The flickering
sounds like a loose connection.

Here is an LED display that snaps into a 1/2" hole, and it may be of higher
quality, for about the same price:
http://www.newark.com/wamco/wl-1091qm7-12v/led-indicator-0-5-14v-yel/dp/86T5470
or this for $1.39
http://www.alliedelec.com/search/productdetail.aspx?SKU=70081830

Yellow is much more common than orange. And here is one for $0.79:
http://www.mpja.com/12VDC-LED-Panel-Indicator-Amber-8mm-Round/productinfo/17304+LE/

I realize it's easier to go to your local Radio Shack, and they should have
what you need. But their quality and selection are not very good. You might
also check an auto supply store for indicators meant for automotive use.

Paul

 

[Jamie]

Never known an indicator LED killed by solar exposure. The ancient ones
were too dim to see in strong sunlight but that is a different matter.

Well I don't know if solar exposure is killed your LED as in it not
being Photalic any more? It could be. An LED does behave like a photo
detector. It is sensitive to light, as well as it being able to emit it.

The case is domed and it's like a magnifier glass. On top of that,
heat can distort the case, causing deformation of the leads
in side.
That is my take on it.

It crossed my mind after I had posted that the starter motor back emf
probably exceeds the reverse bias to kill an LED not protected by a
diode. Tractors are very harsh environments so the poor LED will require
a bit more protection than just a series resistor. Inductor in series
and diode in parallel should tame the electrical environment.

Just get a couple of zener diodes. I think they still come two in a
package from the shack. Put them back to back in series and put that
network across the leads of a good LED. a couple of the 5..6 volt types
should work and I think the shack as those, two in a package.

Jamie

 

[[email protected]]

Fun! Here's a scan of my Ferg, with the boy on top. (~ 10 years
ago.)
http://bayimg.com/AaOGmAAdo

All my 'farm' vehicles are in various states of repair. Mostly fixed
enough to just get the job done. (I wish I had more time.) That's
why I always have to check fluid levels... There's always a chance the
water, oil or hydralics developed another leak.

George H.

That's a nice looking tractor. I've seen lots of Internationals, John
Deere, and Fords, along with some of the lesser known types such as
Alice Chalmers, Minneapolis Moline, Cockshutt, and a couple others, but
your's is the first Fergeson I've seen.

Thanks for the photo.

My Farmall Super M is very dependable. Starter drives are my biggest
problem, and the brakes are always needing some attention. Other than
that, I just need to change the oil, add gas, and make sure to grease
all the fittings regularly. And of course replace tires that cost more
than the tractor did.

Besides re-painting mine. I replaced all the old wiring with new wire,
that old cloth stuff was in poor shape. I also had to shim the steering
gears, or I'd have to turn the steering wheel 3 inches before the tires
would move (typical on all the Farmalls, just as the brake issues and
starter drives).

 

[Martin Brown]

This is NOT a bare LED. It's in a holder with insulated wires coming
out. All I did was drill home in tractor switch box, insert and tighten
the nut. Connected the ground wire to the frame, red lead to the wire
screw on the ignition switch. I made pigtails (since the LED wires were
short), put spade terminals on their ends to connect to the ign switch
and ground. Used very small wirenuts to connect the LED wires to the
pigtails. (I do have a ground wire from the battery terminal to this
control box to insure a good ground, since this tractor is old, there is
some rust where things are bolted, so this makes a good ground)

The problem has been identified elsewhere in the thread. Your LED is
almost certainly being killed by the back EMF from the inductive load of
either the starter motor or spark coil. You need a second resistor in
series and a diode in parallel to prevent the reverse voltage of the LED
being exceeded by voltage spikes from the ignition/starter motor.

 

[[email protected]]

The TO20,30 are very much like the Ford 2N, 9N tractors of the same
vintage.
There’s a Masey-Fergeson dealership up the road from me. They must
have sold a lot of them in their day, because I see them all around
where I live.
I got the tractor for ~$700, but it had water in the oil and I had to
rebuild part of the engine block and piston sleeves before I used it.
(Much to the chagrin of my wife, as the tractor spent its first few
months in pieces in our garage.) Since then I’ve had the head rebuilt
and last year the hydraulic pump. It’s always something. I’ve yet
to put new tires on it. It doesn’t get much work, mostly just
dragging a mower deck around the yard and trails.

George H.

Now that you mentioned Masey-Fergeson, I know where the name came from.
Masey-Fergeson is a name I've heard quite a bit, but most of what I've
seen with that name is other farm machinery, such as balers, combines,
hay mowers, etc. I'm guessing that Masey bought Fergeson, and combined
the names. Your tractor must have been before that merge.

I kind of think that aside from the 3 major names JD, Intl, and Ford,
the other lesser common brands are more regional, due to where they were
made and sold.

I got a GMC truck that needs a rebuild for the same reason. Coolant in
the oil. I'm looking for a different engine, seems easier to change it
than rebuild it, but old tractors are a whole different matter, engines
are not easy to find.