95 S10 Blazer won't start

[unidraggon]

my 95 Blazer (V-6 4.3 L, Letter W) won't start. Don't hear fuel pump when turn the key on.

Replaced the battery and ignition switch in it the end of August. It ran fine for about 2 weeks, then when I came out of a store it would not start. has not started since Mid- September.

Have been told by friend that there is no power going to fuel pump. Not sure what direction to look to fix it.

Anyone know what the problem might be. Need to get back on the road really soon.

Thanks for any advice or help that anyone could give me.

[blazes9395]

Well, you have to make sure you have current at the pump by probing the wires at the pump. If you have power there, then you can safely assume your pump needs to be replaced. On the other hand, if you have no current at the fuel pump connection when the key is turned, you have to figure out whats causing that. If could be a bad relay, bad fuse, wiring, etc, etc.

You can check for current at the pump connection, in the back, on the top of the tank. You can reach that connection without pulling the tank, by patiently trying to get to the connector.

[DelCoch]

On the '95 W engine - there is a red fuel pump test wire located under the hood, on the driver's side inner fender, next to the black electrical junction box. It will be a red wire with a black or gray end and won't be connected to anything - just hanging there. Apply a 12v supply to this red fuel pump test wire and the fuel pump should run. (When you apply a 12V supply to the red fuel pump test wire it will by-pass all other electrical components in the fuel pump circuit)

If the fuel pump runs when applying a 12V jumper to the red fuel pump test wire, then check fuel pump pressure at shrader valve while pump is running. Pressure has to be above 60 psi for engine to start. If you have proper pressure, disconnect jumper wire and observe pressure drop, it should only drop 3-4psi. If it drops more than this the pressure regulator is probably bad.

If all the above checks out your pump is ok, in which case remove the jumper wire and with just the key turned on, conduct "A" and "C" below - (skip "B"). (Remember, when the key is first turned on the pump only runs for 2 seconds and then the key must be off for 10 seconds before the pump will run for another 2 seconds)

If the pump doesn't run when a 12v jumper is applied:

(A) Disconnect the wiring harness at the fuel pump connector at the gas tank.

(B) Again apply a 12v supply to the red fuel pump test wire and leave it there while checking for current on the Grey wire at the fuel pump connector at the gas tank. You can check for current with a test light or volt meter, but in any case make sure you have a good ground when testing.

(C) If you have 12v on the Gray wire and the black wire is supplying a good ground and the pump doesn't run, make sure the connector at the gas tank is making a good connection. If pump still doesn't run, its toast and needs replaced.

Report back with your findings and we can take you further.