JimmyL,

Using battery connector is OK for a ground but its not necessary to disconnect the connector as long as everything is turned off. Even if a low current consumer is on, it shouldn't make a difference because its practically a dead short from the frame and engine to the battery connector.

I would say you GP are all OK. That's exactly what they are supposed to read. Isn't that an easier way to check GP than removing them?

P E H