Hot coil

[super99]

The Oliver 1550 is giving me fits again. On the KXEL tractorcade it started dieing but would start right back up after 2or3 tractors went by, did it 2 or 3 times. I had another condenser, so I changed it and it ran great for an hour or so and did it again. Replaced it with another condenser with the same results but when we stopped I touched the coil and it burned my finger. I called THE Company in Mt Pleasant and they had a new coil so I picked it up when we got back and changed it. Last day was a short one, I touched the coil when we stopped and it was too hot to touch. I put a new distributor from Korves in and replaced the key switch on recommendation from my favorite repair shop. Started and ran great. I took it on a tractor ride yesterday and after about 3 hours it would die and restart in a second or so and keep running. Did this several times. When we stopped for lunch the coil was too hot to touch. New distributor, new coil, 2 condensers ,switch and it still doesn’t run right. New coil bad already? What to try next?Any way to test the coil? Frustrated Chris

 

[Dieseltech]

Does the coil REQUIRE a resistor? If it needs one and does not have one that will make them HOT. Main reason I'll only use a diesel, or I ain't going. Already have 2600 miles on so far this year.

 

[old]

The Oliver 1550 is giving me fits again. On the KXEL tractorcade it started dieing but would start right back up after 2or3 tractors went by, did it 2 or 3 times. I had another condenser, so I changed it and it ran great for an hour or so and did it again. Replaced it with another condenser with the same results but when we stopped I touched the coil and it burned my finger. I called THE Company in Mt Pleasant and they had a new coil so I picked it up when we got back and changed it. Last day was a short one, I touched the coil when we stopped and it was too hot to touch. I put a new distributor from Korves in and replaced the key switch on recommendation from my favorite repair shop. Started and ran great. I took it on a tractor ride yesterday and after about 3 hours it would die and restart in a second or so and keep running. Did this several times. When we stopped for lunch the coil was too hot to touch. New distributor, new coil, 2 condensers ,switch and it still doesn’t run right. New coil bad already? What to try next?Any way to test the coil? Frustrated Chris

Ah but are you using a 6 volt coil on 12 volts with out a ballast resister if you are that is where the problem is

 

[caterpillar guy]

Swap the engine out for diesel and problem solved. Then you can tie the timing cover to a rope for the boat anchor when you go fishing. OR if the boat is bigger just use the whole engine.

 

[wore out]

The Oliver 1550 is giving me fits again. On the KXEL tractorcade it started dieing but would start right back up after 2or3 tractors went by, did it 2 or 3 times. I had another condenser, so I changed it and it ran great for an hour or so and did it again. Replaced it with another condenser with the same results but when we stopped I touched the coil and it burned my finger. I called THE Company in Mt Pleasant and they had a new coil so I picked it up when we got back and changed it. Last day was a short one, I touched the coil when we stopped and it was too hot to touch. I put a new distributor from Korves in and replaced the key switch on recommendation from my favorite repair shop. Started and ran great. I took it on a tractor ride yesterday and after about 3 hours it would die and restart in a second or so and keep running. Did this several times. When we stopped for lunch the coil was too hot to touch. New distributor, new coil, 2 condensers ,switch and it still doesn’t run right. New coil bad already? What to try next?Any way to test the coil? Frustrated Chris

Are you able to measure the primary ignition current? Battery fully charged, engine stopped with points closed, ignition "ON", in round numbers, current should be in the 3 to 4 Amp range, at the low end or less, spark MAY be weak, the higher end of the range and above will cause excessive coil heating and shortened point life. IF current and coil heating is excessive an appropriate resistor needs to be added into the primary circuit to reduce current.

 

[super99]

I still have the old coil, I'll check to see if it has a internal resistor or not. I just came in from putting the tractors away after having them out by the road for the holiday, I started it first and let it idle for about 10 minutes and when I shut it off, the coil was hot.

 

[Janicholson]

The Oliver 1550 is giving me fits again. On the KXEL tractorcade it started dieing but would start right back up after 2or3 tractors went by, did it 2 or 3 times. I had another condenser, so I changed it and it ran great for an hour or so and did it again. Replaced it with another condenser with the same results but when we stopped I touched the coil and it burned my finger. I called THE Company in Mt Pleasant and they had a new coil so I picked it up when we got back and changed it. Last day was a short one, I touched the coil when we stopped and it was too hot to touch. I put a new distributor from Korves in and replaced the key switch on recommendation from my favorite repair shop. Started and ran great. I took it on a tractor ride yesterday and after about 3 hours it would die and restart in a second or so and keep running. Did this several times. When we stopped for lunch the coil was too hot to touch. New distributor, new coil, 2 condensers ,switch and it still doesn’t run right. New coil bad already? What to try next?Any way to test the coil? Frustrated Chris

Coils that need a resistor have a screw terminal to screw terminal resistance of 1.2 Ohms. Coils that do not measure from 3 to 3.5 ohms. a Chrysler or gm ballast resistor works, it would have about 1.5 ohms. Current should be at about 4 amps. Jim

 

[Janicholson]

I still have the old coil, I'll check to see if it has a internal resistor or not. I just came in from putting the tractors away after having them out by the road for the holiday, I started it first and let it idle for about 10 minutes and when I shut it off, the coil was hot.

With respect, and for clarity, no modern coil has a resistor inside. They are just wound with more smaller wire to operate on 14.2 volts during operation. Like buying 12volt light bulbs for 12v operation. Jim

 

[JMOR]

With respect, and for clarity, no modern coil has a resistor inside. They are just wound with more smaller wire to operate on 14.2 volts during operation. Like buying 12volt light bulbs for 12v operation. Jim

Seems that they will never learn that!

 

[olddog]

With respect, and for clarity, no modern coil has a resistor inside. They are just wound with more smaller wire to operate on 14.2 volts during operation. Like buying 12volt light bulbs for 12v operation. Jim

And...to add to JMG's tip, in a points system, if the switch is left on (points closed) with the engine not running, the points and the coil will get hot!
Typically, when the engine quits, it's quite natural to jump off and start investigating with the ignition still on, and the points are closed most of the time. I had to learn that, the hard way especially if you run it out of gas and go fetch some.

 

[BarnyardEngineering]

Is this the first time you've run the tractor for any appreciable amount of time since you've done electrical work to it? Something was changed to cause this. It didn't happen spontaneously.

Most tractors from the 60's and 70's used a 6V coil in combination with a resistor WIRE, not necessarily an obvious white ceramic device hanging out like a sore thumb. So if you rewired the tractor, and used regular wire to supply key power to the ignition coil, there's your problem.

 

[super99]

I still have the old coil, I'll check to see if it has a internal resistor or not. I just came in from putting the tractors away after having them out by the road for the holiday, I started it first and let it idle for about 10 minutes and when I shut it off, the coil was hot.

Is this the first time you've run the tractor for any appreciable amount of time since you've done electrical work to it? Something was changed to cause this. It didn't happen spontaneously.

Most tractors from the 60's and 70's used a 6V coil in combination with a resistor WIRE, not necessarily an obvious white ceramic device hanging out like a sore thumb. So if you rewired the tractor, and used regular wire to supply key power to the ignition coil, there's your problem.

I had a new wiring harness on it when I bought it.

 

[Mike(NEOhio)]

There should be a length of resistor wire in the harness. On mine a wire from one of the small terminals on the solenoid is teed into the wire to the coil. That wire provided full voltage to the coil while cranking only. The coil feed from the ignition switch is the resistor wire, I think it was gray on mine. The tee connection is under the fuel tank above the bell housing.

 

[Fixingfarmer]

Some tractors mostly of the other green flavor have a keyswitch with a resistor on the back that’s visible. Waterloo and Charles city are pretty close to each other some ideas bounced around. It does sound like the key was replaced and you did some rewiring back when you bought it by you and the previous owner and some of the cheaper switches don’t have them.

Doesn’t really matter at this point if there’s only 1.5 Ohms at the coil between the terminals at this point I’d try a coil with 3 or add a resistor I’ve mostly chosen to swap coils since it seems cleaner to me putting a resistor in saves you 20 bucks coils seem to be a bit crazy priced anymore you can spend 50 dollars on one if you want to but to me I don’t like the resistor hanging off the harness it looks like something thrown together even when the manufacturer did it.

 

[Fixingfarmer]

There should be a length of resistor wire in the harness. On mine a wire from one of the small terminals on the solenoid is teed into the wire to the coil. That wire provided full voltage to the coil while cranking only. The coil feed from the ignition switch is the resistor wire, I think it was gray on mine. The tee connection is under the fuel tank above the bell housing.

Looks like they call it the white wire to the ignition terminal. So whatever wire his replaced harness has going from ignition terminal on switch to the coil + should have a 2 ohm resistance or at least 1.5 between the ends or he will have to do something

 

[I550]

I still have the old coil, I'll check to see if it has a internal resistor or not. I just came in from putting the tractors away after having them out by the road for the holiday, I started it first and let it idle for about 10 minutes and when I shut it off, the coil was hot.

I had a new wiring harness on it when I bought it.

There should be 4 terminals on the solenoid. 2 big terminals for battery current to starter motor. A 10. Gage wire from alternator to charge battery on one of the large terminals. Pink Wire from key switch S to S terminal on solenoid and 2 wires to ign on other terminal of solenoid. My 1650 has a small braid white insulated and a 12 Gage orange on the ign terminal on solenoid. That is if replacement wiring harness was correct for your tractor.

 

[super99]

Wires are off of the coil. Voltage on wire to coil is 12.8 volts. Positive lead on tester to positive post on coil is 02.5 . Wire to coil goes into the wrap, can’t tell where it goes.

 

[Mike(NEOhio)]

Here's what mine looks like. PO had changed the alternator to a 10SI but it had a battery drain so I unwrapped the harness to track it down then re-taped it. The resistor wire is about 3 feet long and doubled in the harness hence the loop. You have the right spot. When you hit the starter the wire from the solenoid is just a momentary bypass of the resistance wire while cranking.

 

[super99]

The old coil had a internal resistor, the new one didn't, so I guess that's my problem.

 

[BarnyardEngineering]

The old coil had a internal resistor, the new one didn't, so I guess that's my problem.

I thought the old coil was getting hot and that's why you replaced it.