Checking Fuel Pump 99 Taurus
Arrowshooter
10-26-2009, 10:27 PM
Have a 99 Taurus with the DOHC motor. Hadn't started the car for a couple of weeks and I go out turn the key and the fuel pump did not turn on. If I turn the Key from Off to Run a number of times the pump will finally kick on and the car will start right up and run great.
Is there a way to run the pump from under the hood via a hot wire or jumping polls in the relay socket so that I can rule out the relay? I think I hear the relay clicking but have no one to help with actually checking. Will a fouled fuel filter cause the pump not to turn on? When the engine is running I do have 32psi of pressure.
Is there a way to run the pump from under the hood via a hot wire or jumping polls in the relay socket so that I can rule out the relay? I think I hear the relay clicking but have no one to help with actually checking. Will a fouled fuel filter cause the pump not to turn on? When the engine is running I do have 32psi of pressure.
jd-autotech
10-26-2009, 11:16 PM
my advise is you probably have an identical relay in the fuse box for say the air conditioning switch the two and see if the problem goes away
Arrowshooter
10-27-2009, 12:25 AM
Yes for the A/C. Swapped them and no change.
shorod
10-27-2009, 07:44 AM
You can jumper terminals 3 and 5 of the relay socket to see if that gets the pump running, but I doubt that's your problem, especially since swapping in a different relay didn't fix it. If the terminals are not clearly labeled at the relay socket, these should correspond to relay terminals 30 and 87.
With the relay removed you could also check for ground signal to relay terminal 1 and power to relay terminal 2 right after the key is turned to Run. These are the relay coil terminals (corresponding to 85 and 86, but not necessarily in that order). It likely would be easier to install the relay though and check for voltage at the fuel pump inertial cutoff switch. You want to verify that, when the pump should be running, you have voltage to the Dark Green/Yellow wire. You'll want to use a test light rather than a multimeter so that you are actually providing some load to the circuit. You could also use a multimeter to test for resistance to ground from the Pink/Black wire at the switch using a multimeter. If you show an open circuit here, then you know your fuel pump circuit has an open between the inertia switch and ground. The open is likely a worn fuel pump.
-Rod
With the relay removed you could also check for ground signal to relay terminal 1 and power to relay terminal 2 right after the key is turned to Run. These are the relay coil terminals (corresponding to 85 and 86, but not necessarily in that order). It likely would be easier to install the relay though and check for voltage at the fuel pump inertial cutoff switch. You want to verify that, when the pump should be running, you have voltage to the Dark Green/Yellow wire. You'll want to use a test light rather than a multimeter so that you are actually providing some load to the circuit. You could also use a multimeter to test for resistance to ground from the Pink/Black wire at the switch using a multimeter. If you show an open circuit here, then you know your fuel pump circuit has an open between the inertia switch and ground. The open is likely a worn fuel pump.
-Rod
Arrowshooter
10-27-2009, 09:52 AM
Exactly the info I was looking for. Thanks.
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