Originally Posted by peter_c
It is not the starter. If your dash lights came on by adding in another ground your problem lies in the grounds. Run a test on all the grounds. Does or did the vehicle have an alarm system? Often they can be found under the dash in a bundle of wires.
I wouldn't rule the starter out just yet but you're probably right. I had a switched lead wire on my truck rub through and was grounding out on the frame. It cooked the starter although that wasn't the original issue, it was also causing weird electrical issues in the truck similar to the OPs.
Have you tried to jump the solenoid to see if the starter is good yet?