sweetsoul

i put an old school small block in my 94 z28.my question is will the tach hookup on my hei drive the tach? or do i need some sort of adapter?

sweetsoul

i got it. i used this diagram.

F-BODY LT1 ENGINE WIRING HARNESS.

VATS 16 pin PASSKEY II
|------------------------|
A8| [] [] [] [] [] [] [] []| A1
B8| [] [] [] [] [] [] [] []| B1
|------------------------|

Slot Wire Color Description
A1 Orn Power feed from ECM BAT fuse #4
A2 Pnk Power feed from ECM IGN fuse #5
A3 DK BLU Fuel enable signal
A4 YEL/BLK Starter enable relay control
A5 GRY "Security" indicator lamp control
B5 BLK/WHT Ground
B7 PPL/WHT Ignition key resistor return
B8 WHT/BLK Ignition key resistor feed

| | Top White 10 pin
|K|J|H|G|F|
|A|B|C|D|E|

K is DK GRN and is the coolant temperature feed to instrument cluster.
J is DK GRN/WHT and is fuel pump replay control
H is empty.
G is DK GRN/WHT and is vehicle speed signal.
F is GRY and is fuel pump motor feed.
A is RED and is Alternator feed to instrument cluster.
B is TAN and is oil pressure feed to instrument cluster.
C is BRN and is oil level feed to instrument cluster.
D is empty.
E is empty or if you have a manuel tranny it is the clutch anticipate signal and is GRY.

| | Top Blue 10 pin
|K|J|H|G|F|
|A|B|C|D|E|

K is TAN/BLK and is (Automatic) torque converter clutch control.
J is ORN/BLK and is (Automatic) park/neutral feed from transmission position switch.
NOTE: If this vehicle is manuel the wire would be LT GRN and would be (manuel) backup lamp feed.
H is LT BLU/BLK and is (Automatic) TCC switched power feed.
NOTE: If this vehicle is manuel the would be be BRN and be (manuel) power from turn B/U fuse # 2 to backup switch and would be brown.
G is PNK and power feed from ECM IGN fuse # 5
F is DK GRN/WHT and is A/C request signal
E is DK BLU and is theft deterrent - fuel enable feed.
D is WHT and is techometer signal to instrument cluster.-tied to this wire!
C is WHT/BLK and is diagnostic request signal.
B is service engine soon indicator feed.
A is empty.

Black Connector 4 pin
|A|B|C|D|
A is PPL and is ignition (crank starter) (connected to starter relay)
B is BLK/WHT Ground
C is ORN Power feed from ECM BAT fuse #4
D is Empty

C100. It's connected to the underhood fuse block.
|A|B|C|D|E|
|K|J|H|G|F|
| |
A is PNK and is power feed from injector fuse 9
B is DK GRN/WHT and is A/C compressor relay control
C is DK GRN and is A/C compressor clutch solenoid feed
D is TAN and is serial data signal.
E is BRN and is Air Pump Replay Control.(connected to AIR-PUMP solenoid relay)-->(RELAY CONNECTED TO BATTERY)
F is BRN and is power feed from FANS/SOLs Fuse 6
G is PNK and is power feed from ignition fuse 11
H is DK BLU and is secondary coolant fan relay control
J is DK and is primary fan replay control.
K is PNK and is power feed from injector fuse 10.