RE: Blazer Wont Start
 

Very good advice.

RE: Blazer Wont Start
 

Ok, you’re right. I did mean fuel pump. I did check the old relay and with my wife starting it, I felt the relay working. I pulled and replaced the relay with a new one and felt the same thing. So my question is, “How does one check the ignition switch?” The SECURITY light does illuminate and flashes as normal. All of my gages work normally too. If it is the fuel pump, I'll replace it. But if it is something else I would really love to find it and fix it. Now that it is home, I am not pressured so much to getting it to a shop.

RE: Blazer Wont Start
 

If the relay is clicking, then most likely it is the fuel pump. To verify further, you could measure the voltage being supplied to the relay, pin 30. Also, verify that you are getting a full 12V to relay pin 86 and have good ground on pin 85, both of which should be in spec if the relay is clicking.

Pin 30 is fed by the ECM B fuse in the underhood fuse block so that would be another source to verify voltage at. If you do not have good voltage there, then you have a problem with the power supply to the fuse box which is likely caused by wire damage and/or corrosion.

If you have good voltage there, the next step would be to disconnect the power connector at the tank and test there. You will also want to test for proper ground at the pump as this utilizes a separate ground from everything else and a compromised ground wire (from corrosion and/or damage) could cause intermittent operation. If both of these check out, then the pump is the likely culprit and should be replaced. I believe the wire colors are the same on a 2001 as they are on a 2000 (what I have a reference for). If that is the case, then the gray wire on the 4 pin square connector is the fuel pump +12V feed. The black wire would be the fuel pump motor ground. There should also be a purple wire which is the fuel level sending unit signal and the black with white tracer is the sending unit return. The gray and black wires are on opposite corners of the connector.

These are things which I would check before dropping the $$ on a new pump. To me, the time is worth it to determine if the problem truly is the pump.

RE: Blazer Wont Start
 

I'd agree that is is very likely to be the pump if the relay is working. Could also be the wiring going to the pump, though very unlikely. Could also be the electrical connector on the tank (a little more likely). But most likely is the pump. To test the the wiring or connector you have to do most of the work anyway so if it was my vehicle I would probably just get a new pump and do it regardless.

RE: Blazer Wont Start
 

Would rather test and return a pump if things don't check out right though... Your call.