overdrive not working

fuse Ok wiring seems good. new really fitted . No 'clicking' when activated on lever and ignition on with gearbox in 4th gear. ( or any other gear) was working but just stopped .any advise ? no idea where to start checking. theres a very small 'micro' with on throttle body actuator . no clicking or voltage noted when closing /opening throttle. any suggestions other than sell it? this is a mates car and gentleman is suffering ill health hence my trying to assist in any way.


Active Member
Do you have a wiring diagram? I think the throttle needs to be partly open for the O/D to work , not closed . The solenoid is fairly temperamental. I would look to that first. It has two coils , one to actuate it and one to hold & there is a set of contacts inside, working the actuating coil, give that a clean. Which model of P4 and year will help. You should get the 12V at the solenoid , in 4th gear and throttle at partly open
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Active Member
Rover Laycocks that I drove were manually activated, but the 105R unit might have been governor activated. Dont recall if there was a relay involved. As above , apply +12v directly to the solenoid and it should pull the lever. The 2 windings are know as pick and hold, used to reduce current drawn once pulled in.
jp P2,P3,P4,P6x3,RR,Disco x2