The pix makes me think it is passenger side for RHD, it looks like the heater box flap levers in the background. So in US that would be near driver's right knee? And the amp has a ground thru pin 1 in a header, and more good news, it is in the center console. See attached. C0708 pin 1.

 

Yes, I though drivers side knee as well. I looked on both sides just in case. There is a large chunk of Styrofoam behind the drivers side that feels like its in there real good and didnt want to try to pull it anymore. The search continues...

 

Eliminate the easy problems first… test that relay!

 

OK, so got the Styrofoam out of the way under the drivers side and found the ground point....unfortunately there is nothing connected and no sign that anything was or should be, no hanging wire anywhere I could find. See attachment. Relay checks out good. I guess I will have to go hunting for the amp ground later.

The build dates I have been find as I take stuff apart is April 2004. Does anyone else's 04 head unit not grounded here?

Maybe time to give Paul Grant a call about a replacement amp?

Also, another symptom, ran into a store today and when I came back out most of the speakers where on with static and various other tones loud enough I could hear them from several feet away. Had to open the door, turn on the head unit and then shut it off to make it stop.

 

Fixed!!! I'll give it a week on the battery drain problem, but took apart the amp today and found a burst capacitor and some pretty good corrosion on the PCB board around it. Rebuilt it from a spare I got from Paul Grant and now speakers sound great! No more popping, buzzing or static and all speakers are working. So far no speakers are staying on after the truck is off.

Thanks to everyone for their suggestions and help. Great forum!