Several weeks ago, my 2001 Sable with 185,000 miles, had moments when it would not start up. The fuel pump did not hum that it had pressurized the fuel line. After waiting 30 or so minutes, the pump powered up and the car started. Now, it will not power up. I have checked relays and have swapped several around. No change. I ran a wire from the inertia fuel switch to a multi-meter to the battery negative. When the key is turned on, I get 9.65 vdc for less than a second.
I checked by the pcm and found a ground to frame. It showed only 4.5 volts from the battery positive to it. Ran a new wire from that ground point to battery negative. Now get 12.x volts. No change for the pump. I know it could be the pump, but is 9.65 vdc the proper voltage to the pump?
I am new to the membership. Have searched the site for someone who may have already had this.
Any suggestions or thoughts are welcomed.

 

no it is not 9.65 volts to the pump it is supposed be 12 you could have a bad connection to the pump or a few other things that would cause that condition

 

Thank you for that information. I will continue searching for the breakdown in supplying power. Would running a wire direct to the inertia fuel switch for a few seconds be okay?

 

people do it all the time, so why not. all that will do is make the pump run all the time bypassing the relays is all that you're doing

 

Thank you again for the information. I just want to make it pressurize the fuel line. Will try after work tomorrow. I will post my results.
Thank you also for posting with the code reader thread.

 

So I tried 12 vdc to the fuel pump at the inertia fuel switch. Had the key on. Did not hear the fuel pump power up.
Next step: drop the tank and look at the pump. This make take a few days. I have to get the car raised up enough to work under it.

 

Okay, a follow up. I did drop the fuel tank and found that a mouse had chewed the insulation off of several of the wires. So I replaced the pump from Auto Zone and the fuel filter too. After getting the tank back in place and checking for leaks, pumped hummed properly. Car started. That is all.

 

glad to hear that you got it going. good luck with your car.