I KNEW you'd ask that! It's sockets 1 and 2. There is a long row of sockets once the relay is removed, 1 and 2 will be at 1 end of the rows directly across from each other. If you use a light you should see the numbers in the connector. The relay is remove by twisting the knob on top of the relay. Kind of tricky to get the catches in place to put the relay back in. If you operate the knob a few times with the relay removed you will get an idea of how it works, that will help. If you have someone to turn the key on and off a few times, you should hear the fuel pump run for a second or two every time the switch is switched on, this may help you decide if removing the MAS relay is worth the hassle. If no pump runs, then it's the best next step.
Correct, the MAS takes the place of the fuel pump relay and Klima relay in 1990. It also provided the current to run the O2 sensor heating coil. It had a few other jobs also. NO fuel pump relay on a 1990.
Yes, the fuel pumps (there are a pair under there) are kind of ahead of the right rear wheel above a plastic panel.
I don't know what you can buy at radio shack to jump the pins. I think maybe a small electrical jump wire may work if it had small alligator clips. i have jumper wires made up using a section of wire and the appropriate size "pin" that plugs in to the sockets on the connector. There is no one "right" answer, I'm sure you can make something work.I wouldn't use an uninsulated wire though, use some type of electrical wire, not like a piece of wire clothes hanger or something.