Where is the fuel pump relay on a 1990 Jaguar sovereign, also is there a way to get into the trunk with out a key and the electric lock is not working. (there is no crawl space behind back seat)

in the trunk fuse box

Repair your vehicle right away. Just click on the link I attached 1995 jaguar x300

If the key won;'t work, your only other solution is to remove the rear seats. You may be able to reach through the rear seat bulkhead and pull the release catch.

Similar problem on my 1994 Sovereign; found earth post next to left hand fuse box corroded; (large grommet in inner wing just above fusebox is prone to leaking so sealed with mastic)cleaned and fitted additonal earth to new point on body, now runs fine.

Obviously, the pump is not receiving any power and your rube goldberg is not doing the trick. Get a hold of a schematic and you will do the job right. In the meantime just hookup a wire from the battery plus terminal to the pump plus terminal with a on/off switch so you can turn the pump on and off manually.

this is the fuel pump itself that has failed, replace it. It is located inside the fuel tank and is sold as a module assembly about $675
BOSCH Part # 67935 {Fuel Pump Assembly}
or as just a pump which you splice into the old sender assembly fuel pump module for around $120
AIRTEX Part # E2314 {In Tank Electric Fuel Pump}
Strainer included with pump.

Fuel Pump Relay

Located under passenger's dash panel on yellow connector block.

Is the key you are using green? If so, it is the Valet Key and it will only lock the door - it will not work on the glove box or the trunk.

the key should open the door without any batt power central locking is batt , the key should open both front doors!!owered so it should not be a problem !

Hi irvj6ohn:
The 1993 and 1994 XJ6 Fuel Pump Relay is located in the trunk of the vehicle on the right hand rear side. It is light blue and black in color.
I hope this helps.

Regards
bobbyapal94