June 2014 took trip of 600 miles in 2 days. o/d worked fine. Car sat for 5 days then drove 50 miles working o.k. then o/d would not engage. Removed fuse from relay, pulled handle out. Drove 550 miles in 2 days without o/d. Then removed solenoid at home & it bench tested o.k. Replaced it with a used solenoid & it worked fine for 800 miles over 5 months. Now o/d will not engage again, just like before. Fuse on relay is o.k. Is the solenoid the problem?