I want to set up a fast idle on my '82 6.2L. How should I go about doing this?

Is the fast idle on start up just an adjustment of the throttle?

Engine running, disconnect the fast idle electrical connector at the solenoid, Check to make sure the plunger is not touching the throttle lever of the pump, adjust the idle speed using the screw in the lower part to the throttle lever, (screw threaded end rests against a post coming out of the pump housing) turn screw clockwise to increase idle speed, counter-clockwise to decrease speed.

With curb (hot) idle speed set, connect a jumper wire from B+ to the fast idle solenoid, open throttle to extend the solenoid plunger, adjust the 1/4" hex end of the pushrod to the desired speed, disconnect the jumper and reconnect the existing wire.

Recheck fast idle speed on cold startup, it may need a slight increase depending on how warm the engine was when you performed the above-mentioned adjustments.

I mean like a toggle switch for times when you leave it running after the cold start up fast idle has disengaged.

Ok, sorry for the discourse, you lost me. Just provide power from the ignition switch or the fuse panel (hot with the key on) to one terminal of the switch and then, wire from the other terminal to the solenoid. Solenoid mounting bracket provides the ground.

Adjust the solenoid as I've decribed above with the switch turned on and the plunger extended, the tip should be against the throttle lever of the pump. As you turn the hex head adjusting screw clockwise, it raises the fast idle speed. The hex screw I've referred to is the shaft that runs through the solenoid. If you push on the hex end you'll see the shaft move the throttle lever.

Thanks Fred

I put a toggle switch in my dash for my fast idle and for the fuel advance since I don't have a computer for my diesel (retrofit).