Glow plugs always getting power!?

[cleatus12r]

Here's the diagram that I came up with (15 minute drawing in MS Paint). The blue lines are the DVOM leads and they are labeled next to the picture of the DVOM. Also notice the broken battery cables above the negative terminals.

Is this correct?

If this is how you had your DVOM hooked up and how the truck wiring was configured, then what you see on the volt meter is exactly what should be showing on the volt meter.