Express Duramax Viper 4806VB and Int-SL

2006 Chevy Express Duramax, installing Viper 4806VB and Fortin INT-SL+ no factory alarm, no interest in alarm functions. I've done some searching and have a couple questions. 1. with no interest in the alarm is there any need for the hood pin wiring? 2. I've seen some conflicting opinions about connecting the tach output from the ECM to one or the other of these units, is there any reason not to connect both during the bench prep? 3. Also seen conflicting opinions on whether the door lock and unlock connections need to be made between the two during bench prep...it's just a couple wires, any reason not to do this? Here's what I have: Viper 4806 Main Harness, 6-pin connector H/1 RED (+)12VDC CONSTANT INPUT --- shared with 8-pin Remote Start7 RED/WHITE and INT-SL datalink red) to 12V constant red/black C200 pins B5 or D2 @ column H/2 BLACK (-) CHASSIS GROUND --- shared with 24-pin 13 BLACK/WHITE and fortin datalink black to any solid existing shared ground screw/bolt H/3 BROWN (-) 200mA HORN HONK OUTPUT--- to tan C200 pin A1 (-) wire at column H/4 WHITE/BROWN LIGHT FLASH ISOLATION WIRE - PIN 87a light flash relay-- not used H/5 WHITE PIN 30 of LIGHT FLASH RELAY--- to INT-SL Pink/Black * set Viper to (-) Parking Light output H/6 ORANGE 500 mA GROUND WHEN ARMED OUTPUT—not used Door Lock, 3-pin connector 1 BLUE 500mA (-) UNLOCK OUTPUT to INT-SL White 2 EMPTY NOT USED 3 GREEN 500mA (-) LOCK OUTPUT to INT-SL Light Blue Remote Start, 8-pin connector 1 RED/BLACK (+) 12VDC CONSTANT INPUT for ACC and starter relays splice to 4 RED (+) 12VDC CONSTANT INPUT for ignition 1 relay use 12gauge run to 12V constant@ ignition harness (red/black) C200 pin B5 or D2 2 PINK/BLACK (+) FLEX RELAY INPUT 87A key side (if required) of FLEX RELAY      not used 3 PINK/WHITE (+) IGNITION 2 / FLEX RELAY OUTPUT--- to C200 pin C5 white ACC/Run/Start 4 RED (+) 12VDC CONSTANT INPUT for ignition 1 relay ---to 12V constant(red/black) see pin-1 details 5 VIOLET (+) STARTER OUTPUT --- to C200 pin C1 yellow starter/crank wire 6 ORANGE (+) ACCESSORY OUTPUT --- to C200 pin B6 brown acc wire. 7 RED/WHITE (+) 12VDC CONSTANT INPUT for ignition 2 and flex relays --- to 12V constant (shared with H1) C200 pin B5 or D2 8 PINK (+) IGNITION 1 INPUT/OUTPUT --- to INT-SL Pink Auxiliary/Shutdown Harness 24-pin connector and run to pink ignition 1 wire C200 pin C6 24 Pin Connector: 1 PNK/WHITE (-) 200mA Ignition 2/Flex OUTPUT          not used 2 BLUE/WHITE (-) 200mA 2ND STATUS /REAR DEFOGGER OUTPUT --- Not used 3 RED/WHITE (-) 200mA TRUNK RELEASE OUTPUT to INT-SL Light Blue/Black not used 4 BLACK/YELLOW (-) 200mA DOME LIGHT OUTPUT --- to BCM C4 pin B9 Dk Blue/White courtesy light signal on 5 DARK BLUE (-) 200mA STATUS OUTPUT to INT-SL Blue 6 WHITE/BLACK (-) 200mA AUX 3 OUTPUT              not used 7 WHITE/VIOLET (-) 200mA AUX 1 OUTPUT             not used 8 ORANGE/BLACK (-) 200mA AUX 4 OUTPUT           not used 9 GRAY (-) HOOD PIN INPUT (NC OR NO) --- whatever comes with the viper (why do I need a hood pin if I’m not running a factory alarm?) 10 BLUE* FACTORY HORN INPUT    not used 11 WHITE/BLUE ACTIVATION INPUT not used 12 VIOLET/WHITE** TACHOMETER INPUT --- to INT-SL Orange/Black and route to C100/ECM blue/white tach output wire 13 BLACK/WHITE*** (-) NEUTRAL SAFETY /PARKING BRAKE INPUT      to Chassis ground (auto trans only) shared with H2 Black 14 GREEN/BLACK (-) 200mA FACTORY ALARM DISARM OUTPUT            not used 15 GREEN** (-) DOOR INPUT    not used (manual trans only) 16 EMPTY ------------------------------------ 17 PINK (-) 200mA IGNITION 1 OUTPUT           not used 18 VIOLET** (+) DOOR INPUT             not used 19 VIOLET/BLACK (-) 200mA AUX 2 OUTPUT             not used 20 BROWN (+) BRAKE SHUTDOWN INPUT --- to pin-A white wire @ brake switch connector 21 VIOLET/YELLOW (-) 200mA STARTER OUTPUT        not used 22 GRAY/BLACK (-) DIESEL WAIT TO START INPUT   route to C100 pin C4 Dark Blue 23 ORANGE (-) 200mA ACCESSORY OUTPUT --- not used. 24 GREEN/WHITE (-) 200mA FACTORY ALARM ARM OUTPUT not used FORTIN INT-SL+ Light Blue Lock to Viper 3 GREEN 500mA (-) LOCK OUTPUT White Unlock driver 1 to Viper 1 BLUE 500mA (-) UNLOCK OUTPUT Pink_ Ignition to Viper 8 PINK (+) IGNITION 1 INPUT/OUTPUT Blue_ (-) while running to Viper 5 DARK BLUE (-) 200mA STATUS OUTPUT Orange Door trigger not used Purple Class2 Data to OBD2 pin-2 purple or any SP205 connection Yellow not used Light Blue/Black trunk not used White/Black Unlock driver 2 not used Pink/Black Parking Lights not used Green not used Orange/Black Tach to 12 VIOLET/WHITE** TACHOMETER INPUT and route to C100/ECM tach output wire Blue/White Purple/White not used Yellow/Black not used DATA-LINK cable Red to Viper H/1 RED (+)12VDC CONSTANT INPUT Black to Viper H/2 BLACK (-) CHASSIS GROUND Blue not used White not used Len

2000 Express Hightop Duramax Allison 4x4

What is the function of the hood pin switch? What system/circuit does it control? Edit: Found the answer for this. Still would like to know if there is any downside to connecting the Tach Signal to both the Remote Start and Bypass units?Len

2000 Express Hightop Duramax Allison 4x4