Ωhm

Pin B (BLK/WHT) Don't know. This is new to me. Suspect Ignition Key Warning Switch.

LH Door Jamb Switch is a dual (two wire) switch to ground. One for lamps, one for buzzer. Technically speaking buzzer shouldn't work with the KEY OUT. I think removing wire from C276_B might shut off buzzer. Not sure what it will do for the Headlights ON buzz (doesn't seem to be tied into it). If you try this, let us know.

Check out Dark Forest Green. Run that by the wife.

Great find. Keep it as is.

I think so, traps prime (KEY ON) pressure, prevents fuel rail from draining back to the tank (long CRANK times).

Everyone needs a test light. Voltmeters can fool you.

12.6vdc battery, 14.7vdc alternator, that makes for 2.1vdc charging (counter) voltage for the battery. Normal

Check G102. Lower side of dash, near steering column. Black wire on eyelet.

The perfect place is where engineering put it. Keep in mind any location hotter or colder, fuel trim will compensate for because O2S is boss and 14.7:1 will be maintained. Unless location is so hot or so cold ECU may default to OPEN LOOP.

You could just ground Fuel Pump Relay Block Pin_2. You must keep in mind that the fuel pump will run anytime the KEY is ON. So you can't sit there and listen to radio, your fuel pump is running.

One last call, make/break C200 a couple of times. See if problem goes away.

I hate to spend your money, new Fuel Pump Relay, now suspect ECU.

Pin_2 at the relay block is the wire that goes to the Engine Control Unit (ECU). This wire controls the ON/OFF of the relay coil. The easy testing is done, time to dig out the ECU and disconnect the connector. Examine C200_6 for proper connection. With Fuel Pump Relay removed, check continuity between Fuel Pump Relay Block Pin_2 and ECU C200_6. Looking for 0Ω's. If continuity exist, suspect ECU, otherwise repair OPEN circuit.

With Fuel Pump Relay installed, can you jump Fuel Pump Relay Block Pin_2 to ground? If so, turn KEY ON. Does Fuel Pump run?

With KEY ON and Fuel Pump Relay removed, take voltage reading at Fuel Pump Relay Block Pin_5.

With fused jumper wire in-place, take voltage reading at D1_6 again.

Using a fused jumper wire, jump pin_1 to pin_4. Fuel Pump should run.

I hate answering a question with a question, but did you find something wrong?

Undercoating maybe? Need to check wire to terminal connection.

Not yet. Check terminals at the Fuel Pump Relay, under the Fuel Pump Relay Block.

Need to check the condition of Engine Control Harness Splice_K. Splice K is located where the K is with the circle around it.

Swap out Fuel Pump Relay with a known good relay. Retry D1_6 for B+ (Engine CRANKING).

D1_6 is the switched side of the fuel pump relay (fuel pump voltage). Measure voltage on the following pins: D1-5 B+ (Hot at all times) D1_2 B+ (Hot with KEY ON or engine CRANKING)

Normal fuel pressures are 31psi w/vacuum and 39psi wo/vacuum. This change in pressure, vacuum line connected, will keep the pressure constant on the tip of each injector during all driving conditions.

Is that with the engine RUNNING?