OP
Bartman1959
Silver Member
I have no idea. How and where do I check?
1949 8N Won't Start
- Thread starter Bartman1959
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Soundguy
Old Timer
- Joined
- Mar 11, 2002
- Messages
- 51,575
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- Central florida
- Tractor
- RK 55HC,ym1700, NH7610S, Ford 8N, 2N, NAA, 660, 850 x2, 541, 950, 941D, 951, 2000, 3000, 4000, 4600, 5000, 740, IH 'C' 'H', CUB, John Deere 'B', allis 'G', case VAC
Uh, visually check wire from key switch to coil. From the factory power hit a terminal on a resistor board, wire to the switch, wire from the switch to a ballast resistor, other side of the resistor to the coil. Some people add in extra ceramic resistors, or remove the ballast resistor and add in a ceramic resistor. Need to know what you have inline . Too much series resistance = weak or no spark, not enough leads to thermal breakdown and damage to the coil.
OP
Bartman1959
Silver Member
This is the best I could do for a picture. I don't know exactly what I'm looking at here, but this is a view from the battery compartment.
Soundguy
Old Timer
- Joined
- Mar 11, 2002
- Messages
- 51,575
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- Central florida
- Tractor
- RK 55HC,ym1700, NH7610S, Ford 8N, 2N, NAA, 660, 850 x2, 541, 950, 941D, 951, 2000, 3000, 4000, 4600, 5000, 740, IH 'C' 'H', CUB, John Deere 'B', allis 'G', case VAC
That picture shows the OEM resistor and another under it. You need to look at the wiring and see if either, or both are inline with the coil. I see wires on the OEM resistor, but can't see where the go or if the other resistor is hooked up.
OP
Bartman1959
Silver Member
That's going to have to wait until tomorrow, we have a storm just rolled in. I'll remove the tool box so I can get a better look, and a better picture for you. Did the ohms reading tell you they were too low?
Soundguy
Old Timer
- Joined
- Mar 11, 2002
- Messages
- 51,575
- Location
- Central florida
- Tractor
- RK 55HC,ym1700, NH7610S, Ford 8N, 2N, NAA, 660, 850 x2, 541, 950, 941D, 951, 2000, 3000, 4000, 4600, 5000, 740, IH 'C' 'H', CUB, John Deere 'B', allis 'G', case VAC
2.7 will be a 12v coil.. But 12v coils on front.mounts still use the OEM resistor.. But not the OEM + another.. That kills spark.
If both are inline, gator clip bypass the extra one and try spark test or starting.
If nada, jump from bay hot to coil top as a spark test. Its ok for a short test.
Post back.
If both are inline, gator clip bypass the extra one and try spark test or starting.
If nada, jump from bay hot to coil top as a spark test. Its ok for a short test.
Post back.
OP
Bartman1959
Silver Member
I'll check that tomorrow and get back to you. Again, thanks for all your help on this old gem.
OP
Bartman1959
Silver Member
I pulled a plug and checked for spark, it was very weak. I bypassed the ceramic resister, spark was stronger. I ran hot wire from bat to top of coil, spark was very strong. 
Currently I have charger on battery to bring it back up after all the cranking in last couple of days.
Currently I have charger on battery to bring it back up after all the cranking in last couple of days.
OP
Bartman1959
Silver Member
I pulled a spark plug and checked for spark, it was very weak. I bypassed the ceramic resister, spark was stronger. I ran hot wire from bat to top of coil, spark was very strong. Currently I have charger on battery to bring it back up after all the cranking in last couple of days. 
Phillip w
Platinum Member
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- allis Chalmers 185 and massey ferguson 1531
This is better than watching reruns of the show Dallas. I am curious as to the out come. I still hanging in there with electric problem, maybe the ceramic resister. Dodge use to have a ballast resister and if it went bad you were pretty much done until you got a new one. Because you had a hot spark when you went direct to the coil, it lessons my suspicion of the coil. You might measure the resistance on your resister and see what your ohm readings are. I'm curious to see soundguy's thought. I have a hunch that he is pretty good with this particular tractor.