I have a MSD 7230 3 step box and want to use the retard mode for nitrous.
I have a trans brake and use a relay to activate brake. I use 87a off the trans brake relay for the activation of the nitrous relay with an on/off switch for when I don't want to use nitrous. When I bench test everything it operates as it should. The power that goes to the retard pin on the box is taken from the fuel and nitrous solenoid power. When I check with a timing light nothing changes when activated. I have 0 modules in the other 3 retard spots. I've tried a couple different modules to make sure those are not the issue. I've also tried different retard spots on the box itself in case one wasn't working. What am I missing? Is that not how these work? Shouldn't I be able to leave my total timing in the distributor at 36 and take timing out of the box? Or am I thinking wrong?
Any help greatly appreciated. Thanks.

You should not be applying power to the retard pin. The Retard pin should be grounded when you do not want retard. Then remove the ground to activate that stage of retard. All four stages should be grounded when you do not want to activate them.

Yep. "ZERO" chips or grounds.

Yeah I figured it out. Did not have ground when not activated. Wired as it showed in the instructions, but when I was testing in the driveway I had both solenoids unplugged so they were not activating. Problem was when I did that I also took the ground path to the retard away. As soon as I plugged nitrous solenoid back in the timing started working as it should. I knew it was something simple. Thanks.