OK, before anything let me state I tried several searches before posting a new thread but I am having a couple of issues.
The situation is that the truck up and died while driving, will start if fuel is added to intake.
Troubleshot and discovered the fuel pump wasn't kicking on when key is turned.
Replaced fuel pump, still didn't run.
Did some research, discovered that there are issues with fuel pumps so took it back out and it appeared bad, (wouldn't energize when directly connected to a battery, (briefly, of course).
Exchanged pump with new pump, which tested sat when hooked to battery.
Situation now is that the new pump doesn't energize when I turn the key.
I can't find the test connector under the hood, I have the haynes and know approximately where to look, but I cannot find the "red wire" that the book refers to.
I checked the relay, and it appears I don't get any input voltage to it.
Anyone have any idea what I should try next?
I have 0 pressure in the rails, I have even removed the fuel filter and there's no gas pushed when the key is initially turned, so I know I am on the right track.

 

forgot to mention, I actually have another 2000 blazer and a 2001 Jimmy, so am able to swap parts to find the bad one if needed.

 

If the relay isn't energized, I'd suspect either the ignition switch on the steering column, pump fuse, or the computer (ECM).
Can't say where the test wire is for the pump on a 2000, but on my '97, it was on the driver's side, in the jumble of harness stufff between the brake booster and the fender - but on the firewall.

 

Thanks.
I think the ignition switch is my next best bet, although it's probably too much of a pain to swap from one truck to the other.
As far as the wire goes, I searched all over and can't find it. If I did find it it looks like something else.

Another possibility I have run across in my internet searches is the PCM, which I believe is the main cpu, and according to my haynes manual will require reprogramming.

 

Lose the Haynes manual, they're worthless.

In the underhood fuse panel, right next to the fuel pump relay is a single socket in the fuse panel with nothing plugged into it. No labels, just a vacant female socket. The terminal in the socket is connected to the grey wire from the fuel pump relay. It goes directly to the fuel pump. It should show battery voltage for 2 seconds when the ignition is turned to the RUN position. Post your results.

 

Thanks for the info Captain, I will give that a shot as soon as I get home this afternoon, (provided it stops raining).

 

Crap.
Thanks for the info on the other spot to check it Cap, 2 seconds, 12 volts, just like it should have been, however, still nothing pumping.
Does anyone know any connections in the wiring from the relay to the tank or am I stuck hand over handing the wiring?

I will drop the tank tomorrow and check for the voltage going in, but I am 99% sure that what I have is either a bad ground to the pump harness, or, more likely, I have a break somewhere in the grey wire.

 

The relay is in fact switching, and sending voltage to the pump. That saves a lot of fooling around! From the grey terminal at the relay, there are no splices or connectors until you get to the fuel pump module. It's best not to "stab" it when checking for voltage, moisture will get at the copper stranded wire and corrode it. Go right to the pump module connector and check it for voltage there for the 2 second pump prime. Both black wires in the module connector must show less than 5 ohms resistance to ground at all times. If you have voltage and ground at the module connector, the pump is faulty. Are you using aftermarket pumps? (lots of problems with them.)

 

I had an issue last year with my 2000 where I was getting 12+ at the harness, but no ground. I ended up running a ground from the trailer harness as a temporary fix...which reminds me, I still need to fix that too.

 

There are several ground wires that connect to a "ground splice pack" just ahead of the rear bumper, in the middle. Then one wire runs from the pack to the frame crossmember, top driver side corner of the frame. Might have to shine it up if resistance is excessive.