I fried my starter solenoid about 3 months ago by jump starting my 4210 with a 200 amp power boost battery charger, b/c my battery needed to be changed. The 10 series don't have the thermister ,but after I changed the starter solenoid , my tractor would not do start still till I put a new battery on it and it's like it reset everything. It has been working fine ever since. Just remember if your battery gets weak and won't hold a charge, replace it asap.