Rewiring my EFI Magnum - 1970 Dart Swinger
I did look around for vintage Mopar brake switch options and found there wasn't much that was available for cruise control anymore, but I quickly stumbled across the GM option and didn't keep looking. I think that Dakota switch would work though! The G3 system makes a lot more sense, you can use just one switch for the brakes, cruise, and whatever else, instead of the 3 switch system used through the 80s and 90s. I guess the auto makers were slowing implementing computer controls and still felt comfortable using mechanical switches for some things.
The Magnum setup need two normally closed switches, one is used to cut power to the cruise servo and the other is a signal to the PCM (plus a normally open for the brakes). I'm not sure how the PCM uses the input for the cruise system (aka speed control system), but it's also used for other functions. Or maybe it's more accurate to say I'm not sure why one is used to cut power to the cruise servo when the PCM could manage that.
Here's the FSM piece about the signal to the PCM:
I did look around for vintage Mopar brake switch options and found there wasn't much that was available for cruise control anymore, but I quickly stumbled across the GM option and didn't keep looking. I think that Dakota switch would work though! The G3 system makes a lot more sense, you can use just one switch for the brakes, cruise, and whatever else, instead of the 3 switch system used through the 80s and 90s. I guess the auto makers were slowing implementing computer controls and still felt comfortable using mechanical switches for some things.
The Magnum setup need two normally closed switches, one is used to cut power to the cruise servo and the other is a signal to the PCM (plus a normally open for the brakes). I'm not sure how the PCM uses the input for the cruise system (aka speed control system), but it's also used for other functions. Or maybe it's more accurate to say I'm not sure why one is used to cut power to the cruise servo when the PCM could manage that.
Here's the FSM piece about the signal to the PCM: