83 olds 98 OD trans electric short

I have an electrical short in my 1983 Olds 98 OD transmission that blows my gauges fuse. The short has been there since five years ago when the local pro trans shop replaced the transmission. I went back that next day to say my idiot lights weren't working and they assured me it had nothing to do with their transmisson work. Unfortunately, I believed them, and I never could find the problem either. The trans shop will not respond to my request for correction - as yet.
A year ago I had a buyer for the car ( and still do) but he wants the idiot lights repaired. After 6 weeks of perusing store manuals, Library manuals, and Mitchell muck I had to buy the factory manuals.
Well - the transmission soleniod is fed from the "guages fuse circuit - which feeds the idiot lights. So now, who knows: What is it going to take in the way of work to get to that solenoid or diode that is in that transmisssion?
Would you spell it out? Your help and expertise is greatly desired.