I have 1990 240 with an automatic transmission and repaired the wire to the solenoid that had shorted out due to chafing. I’m not sure if the tran’s is shifting into overdrive and that I may have a bad relay or solenoid. Once I repaired the wire and engaged the O/D the O/D off panel light didn’t come on. What is good test to verify that the trans is shifting into overdrive? Also, at what speed does the tran’s shift into O/D?