tachometer , engine

My name is Paul. I have 06 Chevy Express Cargo Van 4.8l V8. And it is missing a Tachometer. I have purchased one. But I am totaly clueless on how and where to connect it. Also I would like to install EngineStart button. It has 3 connectors on back, but it came with no instructions. Any help is greatly appriciateda2jc

In principle... Tacho - 4 wires - red, black, green, white. Red to IGN (+12V when ignitio is on) Black to ground. Green to IgnitionCoil- (or points output etc etc) White to dash lights (park lamp switch). Not sure on engine start button. Normally just 2 wires that connect IGN +12V to starter solenoid (S or start from IgKey) but could be from battery instead. Hence maybe 3 wires - from battery +12V to IGN (to bypass the IgKey) and to starter solenoid (to crank when button pushed). But I have no idea about your vehicle and its wiring, and what any bypassing might do (ie, damage etc). You need to find out more about the EngineStart button, and how it is supposed to operate (or what you want it to do.    Consider this general info only that may help you figure the rest out. Further info will have to come from others...

If you have an ohm meter, I can help you with the switch.  I am assuming that there is an Ignition wire.  An output to starter solenoid wire and a ground wire for the illumination circuit that will light the switch up when the button is depressed.