overdrive question

[oxford]

Hi everyone
I've checked the archives for this, but can't find the definitive answer.
My car is a BN4, not on the road yet but 3/4 through restoration. Anyway, I noticed today while fiddling with stuff to try and get the engine running since rebuild, that the overdrive solenoid seems to be switching on regardless of the position of the dash switch.
The inhibitor switch is working, but when I move the gear lever towards 4th gear the solenoid activates, even if the dash switch is in the Normal position.
I've checked the dash switch and it seems fine. The relay and throttle switch are original, but in good condition and the loom is new. Could this be something to do with the throttle switch adjustment?
Any ideas gratefully received.
Thanks
Matthew

 

[Keith_M]

As a first guess, I say to check the overdrive relay. It should only allow the the overdrive solenoid to be energized by the gear switch if both the dash switch AND the throttle switch are in the ON position.

 

[Healey Nut]

Re check your wiring .

 

[TimK]

The throttle switch bypasses (overrides) the dash switch. If it is "on", the current will flow to the relay even if the dash switch is off. Check the the position of the throttle switch and the current flow.

 

[Keith_M]

The throttle switch bypasses (overrides) the dash switch. If it is "on", the current will flow to the relay even if the dash switch is off. Check the the position of the throttle switch and the current flow.

True, but if you turn off the dash switch and then shift to 1st or 2nd, the overdrive should disengage and it should not re-engage when you shift back to 3rd or 4th. If that's what it's doing (and it's a little unclear from the original post) then I think it has to be the relay or the wiring.

 

[oxford]

Thanks for the advice everyone. Problem solved: the throttle switch wasn't adjusted properly. Easy! Now I have another. I'll start another thread.
Cheers
Matthew