No Crank voltage

[Spool'n Spyder]

I'm not real familiar with the n/t Eclipses but I have a friend that is having problems and thought I would come here for help. He swapped in a 420a long block that he bought off another guy and it will not start. As far as I can tell, there is a yellow wire that goes to the crank sensor, cam sensor, and the vehicle speed sensor that feeds the voltage to all three. That wire is not hot comming out of the ecu. What could it be?

Also, there is a sensor on the back side of the block right before the tranny. What is is that? It has a greenish plug that goes to it and only one yellow wire. It shows to have continuity to the voltage wire for the other sensors when the key is off but not when the key is on. What causes that?

Thanks

 

[Doug99RS]

The sensor with the lime green like connector with a single wire in it is the oil pressure sending unit. There's voltage on the wire because the current path starts at the battery, goes to a fuse, then to the instrument cluster. It then goes through the bulb for the oil pressure light and then out in to the engine bay leading to the sensor connector which has the yellow wire that you've found has voltage on it. When the oil pressure drops low enough, the switch completes a path to ground which completes the circuit which in turn lights up the oil pressure light. With the connector unplugged, you'll show voltage on that wire. Plug it back in so you'll know whether or not you have oil pressure. Also, remove the dummy plug in the second cavity of that connector because it will allow the pressure switch to breath a little bit. Replace the sensor if it's leaking oil.

The other yellow wire that you're speaking of is the 8 volt reference wire for the camshaft and crankshaft position sensors as well as the vehicle speed sensor on 5 speed cars. There's a connector (A-83) that all these wires lead back to prior to going to the ECU that MIGHT still be unplugged. It's located near the splash shield for the left tire, above the transmission, under the battery area. If all your connectors are in place then you will need to go directly to the computer and verify that the 8volt reference is being sent out of the computer in the first place. Pin number 44, connector A-107, yellow, at the PCM is the 8v reference wire.

Also, you'll need to be a bit more specific as to which 2gnt you're working on since there will be a difference in PCM designs from 95 vs 96+ Also, include whether or not it's auto.
Thanks,
Doug

woops.... I'll check the dates next time.