no start 1992 range rover classic

Hi I just bought a 1992 range rover classic that has some problems.. I am trying to diagnose the reason that the truck wont start this is what ive done..

checked the relays both the fuel pump and the main relay for the efi both work fine and when the key is turned on cna hear clicking
replaced the fuel pump
pulled the fuel pump out and tested it on the bench.. works fine
tested the plug that plugs into the fuel pump and am getting 12 volts..
checked the inertia switch and that is fine..
so im not sure what else to check..

when I check the fuses under the passengers seat the 20Amp main efi fuse is blown and is blowing as soon as i turn the key on...
also i was told that with a range rover if there is an electrical issue on a range rover the parking lights stay on.. cause they are on..

on wednesday i am going to pull down the headliner in the rear of the truck and check the fuel pump ground as i saw thats where its located on allsat.. any other ideas what it could be??

Thanks all
A1C Hutchins