Need help understanding this circuit

Hi Guys

I need some help understanding this circuit. By the looks of it, its a simple relay driver with a timer. But for some reason the actual relay does not work when power is applied to the appropriate pins.

This is from a wiring diagram of a Mazda Protege car. The timer is used (i believe) to time the amount of power given to the door lock motors and to reverse their polarity depending on the lock/unlock action.

How do you know the change-over relay does not work.

Could you buy another cheaply?

I'd say you couldn't actually source parts for that even if you could find out what was wrong. Car parts tend not to be off the shelf, so I'd say repairing it would be difficult without buying the whole unit. It is probably the relay but I can't see where you'd get one, except from Mazda, someone will correct me if I'm wrong.

colin55
when i supply power as per the wiring diagram, nothing happens. these relay's are hard to find. unless you search the junk yard. i doubt Mazda would have it as this is from a 1991 protege.

It seems improbable that both sections are damaged. Remove the relay and test it.