No buzz from Frequency valve
I have no buzz from my FV - I’ve had the car for a few months and don’t think it Has ever worked. I’ve checked that I have 12v to one of the FV wires, that I have continuity from the bulkhead to both, I’ve checked that that the ECU has ground continuity from both the relevant wires and that there is continuity from the ECU to the FV and from the relay to the ECU. The ECU also has 12v to it.
I’ve jumpered the RPM relay between the brown and yellow/red wires which I think should give a noticeable buzz at the FV but have nothing. I’ve also disconnected the O2 sensors for these tests as that should give me 50% at the FV I think.
Anything I’m missing before I start to blame a knackered FV or ECU?
Any help or expertise would be greatly received.
Jon.