Alright, in that case I think I have my switches mixed up. I must be looking at the closed throttle switch in my '87.
In the case of the decel switch, it sounds like it allows the control unit to distinguish between the idle state and deceleration state (hence the name of the switch) when there is no accelerator input in both cases.
Thanks for replying. In my case this is more a question of curiosity than actual diagnosis.