1991 440se Central locking fault.
I will try to give as much info as possible to help find this fault.
I fitted an alarm to the volvo with no problems, when i went to fit the central locking control to the vehicle on trying the system i found that the alarm control unit got very very hot and started to melt the wired going to the open and close of the central locking motor. the diagram was followed and i used the wiring for microswitch central locking ( is this the correct diagram) i connected the wires to the Yellow wire and green wire as shown in haynes manual as central locking motor wires.
Since this has happened the central locking will not opperate, although you will hear the other motors trying to operate with a clicking sound.
i have tested the wires from the drivers door and passanger door, i was getting 11.7v on yellow wire when door switch operated and 3 - 4v on green wire when switch operated. i get the same voltages at the passenger door.
As far as i can tell there is no relay, but is there a control unit that might be affected and where is its location.
Any info greatly received.