Mad Farmer
Well-known Member
- Location
- Northeast
Hi folks.
1940 9n original 6V + ground system. Has always started well and runs great when weather is cold. Recently started dying when worked hard brush hogging in hot weather, takes ~ 1/2 hour then cuts out. I get it back home by running a jumper from coil side of resistor to hot terminal on resistor assy.
I've read about the issue with ign keys here.......
I checked all wiring for continuity and voltage when cold overnight and all was fine except one strange thing: both sides of resistor showed a bit of voltage, WITH THE KEY OFF? I checked it again with coil disconnected, thinking maybe coil charge was leaking backwards, still the same. When cold it has battery voltage (6.3V) on both sides of resistor and to the coil. The strange voltage at the resistor w/key off does not drain battery down, it can sit two months and start up.
So yesterday took the multi-meter into the field with me when cutting. When it died I checked voltage at both sides of resistor: key side 4.9V, coil side 2.6 V. Key AND resistor bad? Even after sitting an hour still would not start without jumper wire. Won't start with jumper on key side of the resistor either.
So I ordered a new resistor assy and ign key today. But have a couple of questions???
1) do these resistors work by heating up when current is flowing. That is so you get full voltage when starting but a voltage drop after a bit of running. What is normal voltage drop?
2)Any ideas on the voltage (0.3V) at resistor w/key off? My meter is O.K.
3) How much of a PITA is it to get the mounting screws out of the resistor plate? I'm hoping not to have to remove the hood, just battery. Plan is to hit them with PB Blaster then give them a few wacks with a hand held hammer Snap-On impact driver, if I can get a swing with the hammer........
Thanks for any advice in advance.
1940 9n original 6V + ground system. Has always started well and runs great when weather is cold. Recently started dying when worked hard brush hogging in hot weather, takes ~ 1/2 hour then cuts out. I get it back home by running a jumper from coil side of resistor to hot terminal on resistor assy.
I've read about the issue with ign keys here.......
I checked all wiring for continuity and voltage when cold overnight and all was fine except one strange thing: both sides of resistor showed a bit of voltage, WITH THE KEY OFF? I checked it again with coil disconnected, thinking maybe coil charge was leaking backwards, still the same. When cold it has battery voltage (6.3V) on both sides of resistor and to the coil. The strange voltage at the resistor w/key off does not drain battery down, it can sit two months and start up.
So yesterday took the multi-meter into the field with me when cutting. When it died I checked voltage at both sides of resistor: key side 4.9V, coil side 2.6 V. Key AND resistor bad? Even after sitting an hour still would not start without jumper wire. Won't start with jumper on key side of the resistor either.
So I ordered a new resistor assy and ign key today. But have a couple of questions???
1) do these resistors work by heating up when current is flowing. That is so you get full voltage when starting but a voltage drop after a bit of running. What is normal voltage drop?
2)Any ideas on the voltage (0.3V) at resistor w/key off? My meter is O.K.
3) How much of a PITA is it to get the mounting screws out of the resistor plate? I'm hoping not to have to remove the hood, just battery. Plan is to hit them with PB Blaster then give them a few wacks with a hand held hammer Snap-On impact driver, if I can get a swing with the hammer........
Thanks for any advice in advance.