consultation

Hello everyone to have if you can give me any solution to this consultation in a Volvo B12B bus stay without drum, when connecting the tweezers to start the bus starts but when the key of contact is released to its position it stops the engine, keeping the key in starting position the engine is the relay and can be accelerated by responding the engine but when returning the key to its normal contact position it stops. problem. Thank you

Good Manuel, obviously the problem is in the Drum of Ignition, this same is plastic and is located just behind where you put the key to start. Since the spent contacts are and already fulfilled its useful life. Asked in any house of spare parts how much a pill of universal ignition is worth, you make the connections as correspond and ready the chicken !!!!