1990 DEVILLE. Posted 6-14. New BCM, new fuel pump, new relay, still no fuel. Have tested wires, I get a brief 12 volts to grey wire on connector to fuel pump when key is turned on, then nothing. I can hear the relay clicking when I turn key on, 2 secs later it clicks again. Have tried different relays with same result. Any ideas?

It sounds like you have done some troubleshooting on your own and have determined that there is a problem with the power wire to the fuel pump. Running a new wire from the fuel pump power wire to the relay is a good solution if the original wire is damaged or burnt out.
Before connecting the new wire to the relay, it is a good idea to test the fuel pump by running a wire from the battery positive terminal to the fuel pump power wire. This will ensure that the fuel pump is working properly.
Once you have confirmed that the fuel pump is working, you can connect the new wire to the relay. It is important to connect the wire to the correct pin on the relay. In this case, you should connect it to pin 87, which is the power output pin.
It is also important to ensure that the wire is properly insulated and secured to prevent any electrical shorts or damage. Once the wire is connected, you can test the fuel pump by turning the key to the "on" position and listening for the fuel pump to engage.
If everything is working properly, the fuel pump should only receive power when the key is turned on, and the new wire to the relay will provide a reliable power source for the fuel pump.

put new relay in.
have you checked its not the pump
First, confirm that the pump is bad by listening carefully for the one second hum from the tank when you turn the key to the start position. If you didn't hear a thing..

Check for 12 volts at the dark green with black tracer wire at the wiring connection located underneath the van behind the driver's door. This wire supplies the voltage to your pump. If you have the rear heat this connector is generally found right around were the hoses are for the rear heater. There may be two connections at this location but the one you're looking for is the larger one with four wires.
Connect a voltage meter (or test light) to the dark green with black tracer wire and have someone turn ignition to the on position. Look for a flash of voltage then off. If you get the 12 volt reading that means that the computer ( PCM) has grounded the ASD (auto shut-down) relay circuit.
Now have someone crank the engine while you are still reading the voltage at the wiring connector. If everything is working normally you should get 10-11 volts while the engine is cranking. If you only get a very brief voltage reading or zero consider additional testing of the crankshaft or camshaft sensors (or fuses). If you got any sign of voltage doing the above test but never heard the fuel pump hum, with the electrical connections intact, then there is a strong probability that fuel pump is bad

Pull the pump out and see if just running 12 volts across it gets it to work. If that happens then it is not the pump at all but more likely fuse board or even the body computer.

fuel pump relay: on relay center,behind glove box, 2nd column of relays, 2nd one from the top.
fuse: the wiring diagram says that it is fuse #6 on/by?? the relay center.
there should be a fuel pump test connector taped to the harness by/behind the battery. probably single red wire with a black or white connector. apply 12 volts to connector to test fuel pump.

Sounds like a bad connection between the two points.
It may be easier to run a new wire than to tear the harness and connectors apart.

Your pump is controlled by the pcm using a 12 volt signal to the relay. Pull out the relay and probe the relay socket with a voltmeter. There should be 2 terminals with 12 volts when the key is on. With the key off, there should be one 12 volt terminal coming from the ecm b fuse. See top left of diagram below.

The plug you are referring to is probably the fuel tank pressure sender not the fuel pump. It would be plugged into a black sensor about 2 inches long pushed into a rubber grommet on the fuel bung. The fuel pump connector would have more that 2 wires going to it. most likely a heavy purple wire would be the power to the pump. It has to have 12 volts to it to work. The sender may have 3 wires, 5 volts, ground, and sense. the pump connector would have 12 volts, ground and 5 volts for the fuel gauge sender down in the tank.
If the 12 volts is not there, check the fuel pump relay. it is usually up on the drivers side firewall.
With the key in the on position without starting the engine, you should have 12 volts to the pump for 3 seconds then it will click off. Without cranking the engine you should be able to locate the relay by the clicking sound.
There is also the obvious, like checking the fuel pump fuse.

Replace the oil pressure switch for the third wire on that sends 12 volts to the fuel pump upon turning the ignition key on to prime. Once oil pressure is achived the computer shuts that circuit off and turns on the fuel pump relay to power the pump till you shut off the engine

there were some production changes in 1998 to the fuel pump wiring, so the connector can have 2 diff fuel pump power wire colors, the most common color is grey, but the the harness at the tank has just 4 wires, the larger wires at the four wire oval connector are the fuel pump 12 Volt and the other is the ground, it is black, the other 2 wires are the sending unit, also the connectors ( Chevy factory service bulletin) on this year had a problem with burning, so if you get a new fuel pump always replace the 4 wire fuel pump connector. I have attreached a picture of the connector

I have a silhouette and it had the same problem
Follow the fuel pump wiring harness to where it plugs into the floor of the van--pull the connectors apart--they will probably be corroded, and you will possibly have to change both wiring harnesses or connectors.