Problem M.E.S. 1.7 airbag obd1

[Garychworth]

Hello, I come here for a problem connecting to the airbag ECU on a Bravo OBD1 from 1999, I can connect to the engine ECU with M.E.S. 1.7, a kkl cable and a 3 pin adapter, but I cannot connect to the airbag ecu (nor abs either). he says that the connection is impossible, I am plugged into the 3 pin socket behind the glove box, the 3 pin adapter is connected to 12V, I don't understand how to do it, and what someone can give me the solution ? THANKS