Fuel pump or fuel pump relay

[demonix_racing]

My 97 grand prix wont start it cranks but wont turn over so i dont know if my fuel pump is bad or if its just the relay i wish i knew there is a big price diffrence in the two Ok dump question IS there a way to tell that my fuel pump relay is bad by looking at it or do i have to replace it to tell????? Or is there a way to test the relay thats in my car or is there a way to test the fuel pump how do i know what is bad the pump or the relay plz help

[BNaylor]

The problem you have is I believe the fuel pump relay is one of a kind so you would have to replace it if suspected bad. If you had a GTP there are two fuel pump relays which are interchangeable. The best way to test the fuel pump is for pressure and flow by hooking up an automotive fuel pressure tester to the Schrader valve located on the fuel injector rail.

Also, you can check the input to the fuel pump from the relay with a multimeter. The fuel pump is easy to access by removing the carpeting and sound deadening material from behind the rear passenger seat in the trunk area. The access plate can be removed for inspection and troubleshooting. With ignition to on not start there will be 12 volts at the respective pins on the electrical connector.

[buckeyeguy]

What are the pins that should have the 12V? I tried many combinations and only got 5V. So I thought maybe the relay was bad....that was not the case
I know the pump is not running (it was easy to hear before) but now I want to make sure the pump is the problem. Also, useful info....I replaced the resistor last summer, so I know how that acts and know this is not it.

Thanks for your help guys

[BNaylor]

What year is your Grand Prix? Normally the gray wire brings in the hot (up to 12 volts) to the fuel pump assembly.

Obviously 5 volts is abnormal. What do you have coming off the fuel pump relay contacts. Is there a voltage drop?

[tblake]

Where are you grounding your Multi-meter? Like Bob said, usually Grey supplies Voltage to the pump. I like to measure voltage between grey and black (ground) and then grey and a known good body ground (with no paint or corrosion). It usually helps to rule out a supply or grounding issue.

[buckeyeguy]

Have not checked the relay voltage yet. Went and picked up a cheap on yesterday and still nothing. I am going to go check voltage from the gray right now.
If I check relay voltage...which "blades" should have voltage?

[buckeyeguy]

OK, I did check between the gray and the balck and it flashed 11,89 V for about a second. I know it said it would only for 3-5 seconds but it really didn't last that long.....