Ford 801 6 Volt to12 Volt Change Over

[baydog1]

I have a Ford 801 that was already converted to 12 volts when I bought it. Now my buddy has a has a 801 with power steering and hyd. remote in the back, way nicer than mine but still is the slow cranking hard starting 6 volt positive ground system. Did the switch over to negative ground and switched over to a 1 wire Delco Alternator. Starts, runs and charges like a champ, but I have toasted two 12 volt coils by forgetting and leaving the ignition key on and coil heats up and fries. Does this mean I need to put a 12 volt resistor on the 12 volt supply wire to the coil and the wire coming off the other side of the resistor goes to coil. Will this stop me from frying coils? Can I get this from any auto parts store or this website?

Thanks
Scotty

 

[Janicholson]

Leaving the ignition on is the real issue. Why does it get left on? There could be a light wired from the ignition to the dash that is on when the key is on. If the tractor is not shutting off with the key, what was changed to cause that. Jim

 

[baydog1]

The light is still wired in and worked for a while but being a 6 volt bulb it blew. I thought I could replace with 12 volt version of the same bulb. Yes for sure the key being left on is the problem but I have the same tractor with a burnt out bulb and somehow the key gets left on from time to time but my tractor doesn't fry coils and if the points happen to land open the battery isn't even dead. Still with the key left on and points closed I don't think I should be frying coils.
Thanks
Scotty

 

[john in la]

Lets start with...
What are you calling a 12 volt coil.
They make two distinct types of 12 volts coils and they are differant.

Where are you buying them and what is the part number you are using ????

 

[old]

Coil will fry if the key is left on and points closed due to the coil getting to hot simple fact of how things work. Your lucky the points don't get fried also

 

[tractorguy2]

Anytime the key is left on. The coil and points will fry like bacon.

The Ford hundred series start real good and quick on six volts when everything is in good condition.

 

[Janicholson]

A coil operates at between 35 and 50% of the time. It is a pulse on Pulse off. Thus it has time to cool between the points opening, and closing. Another factor is cooling air blowing across it from the fan. coils generally consume between 3.5 and 4.4 amps of power. Calling it 4 and multiplying by the 12.6 volts of the battery is about 50 or so watts. Can you put your hand on a 50 watt light bulb. no. JIM

 

[stevob671]

How are you shutting a gas Ford tractor off if you don't remove the coil voltage with the key?? I guess maybe turn off the gas and wait for it to run out? The gas Fords we had all quit with the key...which shut off the coil power.

 

[Steve@Advance]

To convert to 12v, the proper coil or coil/resistor combo must be used. Asking the counter person for a 12v coil may get you anything, most likely a blank stare!

The NAPA IC14SB coil is a true 12v, no resistor required coil. Ask for it by the part number and don't take a substitution.

Be sure to check the number on the coil it's self, often they get reboxed, returned, restocked.

There is more to it than avoiding burning the coil up with the ignition left on. Using the wrong coil will greatly reduce the points life.

Even having the correct coil will not prevent damage from the ignition being left on. Just make it a point to never, ever do that!

 

[baydog1]

Yep! They are fried too..
Thanks

 

[baydog1]

Good Point. 50 watt bulb does get hot and it is to hot to hold on to.
Thanks

 

[baydog1]

It cuts off by the key. The bulb is blown which is still no excuse for leaving the key on. Don't know why the key gets left on but looks like the only fix is to check and double check that the key is off before leaving tractor.
Thanks

 

[baydog1]

Don't know about the part # but I ask for a 12 volt coil with built in resister. Bought the last one at autozone and got the deer in the headlight look when I asked for for a 12v coil with built in resistor
Thanks
Scotty

 

[Fred Werring]

I used a Standard Motor Products UF3T Ignition Coil when I changed over an NAA 6 years ago. Have had no issues with it, but is no longer available.

Looks like the replacement is a Standard Motor Products UC15T Ignition Coil, in the link below.

Funny, read your post this morning. Thought thats why I use an idiot light instead of a resistor or diode, so I can see that I left it on

Walked by my 64 4000 that I used yesterday, and the light was on. I'm a dummy. Luckily, it started up.

Don't know about you, but my 4000 has a dieseling issue...why I turn off the gas to kill it. If I stomp on the brakes and pop the clutch to stop the dieseling, it will actually run backwards for a couple revolutions, blows oil out the air cleaner.
Standard Motor Products UC15T Ignition Coil

 

[baydog1]

Thanks for the Standard brand part#. Pretty sure I won't be buying the cheapest coil from the closest auto parts store no more. I don't know how the key gets left on but it happens, I've some how even left the key on in my truck before but the difference is unless the points land open when the key is left on this tractor ain't as forgiven.
On your tractor, Sometimes if the idle is set to high I've had trouble with the dieseling. So I idle them down as low as the tractor will run almost and that usually helps. I like it like that especially when backing up to implements.

 

[baydog1]

So here is the culprit. contacts aren't bad but the lobe is wiped out.
Thanks

 

[baydog1]

 

[old]

There is no built in resister in coils. They are either made for 6 volts or 12 volts. If it says on it no external resister needed it is a true 12 volt coil but if it says resister needed it is 6 volts

 

[old]

When ignition is left on the points get hot and in turn the arm the rub block is on gets hot and melts the rub block

 

[baydog1]

Thanks Steve. That's what I'll be using from now on. They work like a champ!

 

[Janicholson]

If it is in direct drive (TA forward)it won't do that! Jim