HARSHAD J-1214051

Hello All, I'm Harshad from India and found sometime back a three-track Hornby Dublo Three Track Duchess of Montrose with its coal wagon and two coaches. This was bought by my Dad in 1960 from a British friend and now I'm 70 years old, but when it was bought, I was very young. Somehow during all these years, this set was locked in some box, and I decided to restore it. I was lucky that Jack of our website sent me some metal fishplates, that were missing and they were connected. Now tracks fit firmly with no bends. I overhauled by Lock as given in YouTube, by a collector and I have the old transformer "Gray" With two connectors and a black lever for forward and backward movement. Locomotive restoration: Cleaned both carbon brushes and the motor.Checked the two contacts in the center and cleaned them with a light emery paper.Used best machine oil and lightly lubricated the wheel contacts.Somehow when the Loco is connected to one metal pressure plate and sends the second to any black part of the Loco body, it runs both forward and backward. Checked contacts with an electric tester, but no current is passing to the track. Can anyone help me to restore this problem? Forgive my long description, but I badly want it to work. Please help? Harshad J Contractor.