42RH / A-500 in a Duster with pictures.
If you put switched 12v on the center pin and use the other two terminals for switches inside the car you can use the switches to ground or unground the solenoids in the trans for OD and lockup.
You don't want both coming on at the same time though.
Run your 2 separate wires now, so you have it later.
OD will ONLY come on after the trans is in 3rd gear, but lockup will come on any time at any speed if it's switch is on, and will even kill the engine if it's on when you come to a stop.
Lets say you have the OD switch on as you are upshifting through the gears normally.
When 3rd engages OD will come on about 1 second later.
If you run two wires into the cabin from the connector on the trans you can manually choose when each comes on gets turned off.
I have mine set up to run trans pressure off of the governor port, and that pressure switches two adjustable fuel pressure safety switches. (One for OD and one for lockup)
There are also two switches inside the car that bypass the ground for the relays that control the solenoids for each so I can disable OD or lockup either one or both.
This allows me to leave both switches on all the time if I want and let the trans tell the solenoids when to activate each via gov pressure (wheel speed)
If I leave both switches in the "Auto" position the trans automatically shifts at the set speeds via the pressure switches.
This makes it shift 1-2-3-OD-Lockup completely automatically with OD coming on at 55mph and lockup at 75mph.
When I let off the gas and let it start slowing down, lockup automatically comes off at 75 and OD at 55 without having to do or touch anything.
If I turn both switches "Off" then it shifts just like a normal 904 or 727 three speed.
Right now all you need is two wires running into the cabin to two switches so you can ground or unground the two solenoids separately.
I can help with the full auto stuff later when you are ready.
For now you can ignore all the stuff about the LED indicators in the connector pic.
If you put switched 12v on the center pin and use the other two terminals for switches inside the car you can use the switches to ground or unground the solenoids in the trans for OD and lockup.
You don't want both coming on at the same time though.
Run your 2 separate wires now, so you have it later.
OD will ONLY come on after the trans is in 3rd gear, but lockup will come on any time at any speed if it's switch is on, and will even kill the engine if it's on when you come to a stop.
Lets say you have the OD switch on as you are upshifting through the gears normally.
When 3rd engages OD will come on about 1 second later.
If you run two wires into the cabin from the connector on the trans you can manually choose when each comes on gets turned off.
I have mine set up to run trans pressure off of the governor port, and that pressure switches two adjustable fuel pressure safety switches. (One for OD and one for lockup)
There are also two switches inside the car that bypass the ground for the relays that control the solenoids for each so I can disable OD or lockup either one or both.
This allows me to leave both switches on all the time if I want and let the trans tell the solenoids when to activate each via gov pressure (wheel speed)
If I leave both switches in the "Auto" position the trans automatically shifts at the set speeds via the pressure switches.
This makes it shift 1-2-3-OD-Lockup completely automatically with OD coming on at 55mph and lockup at 75mph.
When I let off the gas and let it start slowing down, lockup automatically comes off at 75 and OD at 55 without having to do or touch anything.
If I turn both switches "Off" then it shifts just like a normal 904 or 727 three speed.
Right now all you need is two wires running into the cabin to two switches so you can ground or unground the two solenoids separately.
I can help with the full auto stuff later when you are ready.
For now you can ignore all the stuff about the LED indicators in the connector pic.