I recently purchased a Mevi that was installed on a 1995 Maxima. I own a 1998 Se 5 speed Maxima and would like some advice on some wiring installation. The Summit RPM switch I received has additional colored wires connected to the original wiring. My first question is, do I need the additional wiring, and if so, where would each specific color wire need to be? In addition to the Summit RPM switch, it came with a Vacuum switch that is wired to a 12 volt black box. My question here is, is it necessary to have all the additional wire with the 12 volt box or would I be able to detach the box along the with the additional wiring and use the two wires that exit the vacuum switch? And where would the two wires connect to? I have attached two pictures below depicting my descriptions. I've searched numerous threads, but have yet to discover answers to my questions. Any help or feedback would be greatly appreciated.

 

The additional wiring was simply added because the original length wasn't long enough for the previous user's needs and location of Summit RPM switch. Depending on where you install it, you may want to keep the extra length, or cut it off.

The 'black box' is the relay. It's best to use it, as it will protect the Summit RPM switch from frying.

Summit RPM Switch

Red=switched 12V power source
Black= chassis ground
Grey= Tach signal
Blue= negative/ground side of the vacuum solenoid

A good place to pick up the tach signal in the engine bay, should you go that route, is the #6 coilpack. Tap into the grey w/ red stripe coilpack wire. While you're there, tap the red coilpack wire for your 12V+ switched power source.

I don't see a vacuum canister with built in check valve in your pics. You'll need one if you don't have one already.

In my diagram, replace the Harlan switch with your Summit Switch. In order to set the Summit RPM switch, you're going to need the actual instructions. Download from Summit here.