Using my Digital Meter, I get 6+ volts to the negative wires at my ECU...is this normal? Should negative not be 0 volts? Does this indicate a short or faulty sensor?

Thanks

 

The engine electrical section of the FSM has a complete listing of values for all the pinouts on the ECU.

I have a link to the manuals in my Sig below.

 

some of the circuits are 12v and some are 5 volt.

If you are measuring things like coil triggers or fuel injector tiggers wheil the car is running, they will often look like 6 volts AC (depending on the refresh speed of your meter).

 

You could also have a bad ground connection down stream of where you are measuring the 6v.

By default, a ground is 0V. even if you connect a 12v lead to ground, the 12v will be pulled to 0v (and a little fireworks I might add).

Small differences in ground can be acceptable, i.e. < 0.5v. Even then I would beef up the ground circuit to get everything at the same reference ground of 0V.

A short would not last, a fuse would blow. That is unless you are real lucky and short through some kind of load.