wiring up r/s for display

looking on some input on how to go about doing this project. We're hooking up an audiovox aps-996 and dei 554R in some of those old clifford bubble diplays so we can display to the customers how the two way function of the transmitters work. without an actual tach signal, how can i trick the units into making the remote starter function work so we can demo the remotes to customers? if you use tachless mode, doesnt the brain monitor a voltage increase in the vehicles to know the vehicle is started? I've spoken   with audiovox and they said one of their engineers made a circuit to make something like this work, but im still awaiting a phone call back on that. go figure.... anyone have any ideas?????????????Mike Battaglia

Specialized Car Audio

Bensenville IL 60106

Use a relay. 30 loops to 86 and tach input on rs unit 87 loops to 85 and constant 12v 87a goes to ground to program tach then to ground when running when displaying. I think that should work you might wanna use a high quality relay so it doesn't stick or anything.Tell the Snap-On guy I'm not here!