Can anyone tell me what the 4th wire on the MAP sensor is for? I'm in the process of retro-fitting a common rail MAP sensor for use with a quadzilla commander in my 97. Not sure where to get a good +5 volts let alone what the 4th wire does.
Thanks

 

The MAP connector has two 5v leads. One is 5v power (Light Blue) from the ECM and the other is the 5v feed (Dark Green/Orange) to the Rail Pressure Sensor.

MikeyB

 

Thanks!!
I think I'll supply the MAP with take +5v from the water temp sensor.

 

4 wires...

1. 5vdc common
2. return common [ground]
3. 0.5vdc-4.5vdc ecm return for manifold pressure [boost]
4. 0.5vdc-4.5vdc ecm return for manifold air temprature

not sure what the pin order or color is without a wiring schematic

 

the red is the 5vdc power wire. dark blue for boost, light blue for temp

 

You cant just take 5 volts from the coolant temp sensor , it is a analog resistive circuit, that 5 volts supply has a resistor in the ecm along with the A/D reciever , your coolant temp would never read right again.

 

Any ideas how to make it work?

It's been 2 years of waiting for the analog to digital boost sender from Quad so I'm pretty sure it's not going to happen...