Map Sensor and power logger hybrid

[larrym]

I have a 71 Vega with GN running gear stock computer and wiring harness, the vega wiring runs lights and the starter I have an auxilary fuse panel for the engine managment, alky kit, wideband and fuel system. The C100 bulkhead connector has been eliminated along with that wiring.

So I wired my power logger to the green wire terminal A on C437 like I had it in the Ttype and nothing, the connector is not connected to anything and I have ran power to terminal F to run the motor, there is no power at the map sensor and I have probed the C437 connector terminal G black and white marked as ground has 5 volts? Nothing at terminal B I jumped the G and B together and got a reading of 20 PSI on the powerlogger? Is it as simple as grounding terminal G?

 

[pacecarta]

the reason you have nothing is the map gets its power and ground through that connector from the dash harness tach boost module , you need to run a wire from the tps gray at ecm (pin C14) to pin B (gray) at that connector that will provide 5v to the map connector underhood
then you need to connect the ground on that connector (G blk wire ) to the tps ground at ecm (pin D12 blk)

with 5v at gray wire at map connector and ground at blk wire of map connector the center pin B green wire will have the map signal which for a 3 bar map whoul show 1.6v key on engine off, for a 2bar it should show approx 2.5v

 

[larrym]

Thank you sir I appreciate the insight

 

[larrym]

Can I ground it at the Chassis or is the ECM ground important?

 

[pacecarta]

safest for proper reading is to use the 5v low ground at ecm but it will work if just connected to chassis

 

[hflwyo]

I have one these brand new never used if you want it. It is for people that don't have the 5v from the dash for the MAP sensor. Gets power and ground from TPS sensor, all plug and play no wires to cut. $24 shiipped https://www.alkycontrol.com/product-page/buick-tps-harness-5v