2000 Murcury Grand Marquis No power to fuel pump

There should be a fuel safety shut-off switch in the trunk. Have you checked that?

Thx for the reply, Yes

Fuse in underhood fuse box or fuel pump relay might be bad.

Hey Bob... Thx for the reply. I did check those as well. I should have mentioned that in my post. I swapped relays and will double check the fuse.

Make sure you have power going to the inertia switch. The fuse and relay feed power to the inertia switch. If fuse is good and relay is functioning and no power to the inertia switch, then there may be a problem with the wiring or a ground somewhere.

I am calling the inertia switch as the red button in the trunk which is depressed AND I jumped it through just to be sure it was not the switch. Is there another switch? I looked behind panel in the passenger's side floor and only found a crash module I believe it was called. Thx

I still think it's the fuel pump relay, buy a new one.

I have swapped both fuel relays for a known good one with no success. I have gone as far as to insure there is not 12 volts in the trunk where the fuel pump wiring enters just to be sure the connector is OK on the outside. Just not getting 12 volts. OK, been doing some reading and I really appreciate the comments so far... What are the chances of either of these being the issue... Mass Air Sensor?? Crank Sensor?? ECM?? ( tried disconnecting battery for about 5 minutes ) Thx so much in advance Mike

do you have 12 v in the trunk, or not? I'd still use a new relay(s). Do you have fuel pressure? Gauges don't cost much. MAF can be cleaned with cleaner (that threw me once on a poor running car). Crank sensor will make it not run, and of course ECM. The big questions is, do you have fuel pressure?

I do not have 12 volts in the trunk and no fuel pressure. The rails are not pressurized. Curious what about the PATS system in the car ( red light on the dash ). I do have 2 keys and neither will allow the pump to run?? Both keys exhibit the same flashing sequence when attempting to start the car. How would I know that the chip is triggering the ECM??

I will try new relays as well but will not be right away. I do understand your point about new relays

Not throwing any PATS codes. I do have a code reader

I don't know anything about that PATS system, but I'm sure that's what it is, since you have no fuel pressure, I've seen others having problems with that, none of my cars have ever had it, or I'd probably know about it. I guess it's some kind of anti-theft. Were your keys programmed?

Anti theft would cut the fuel pressure, even if no codes. Try googling it. I just don't trust used relays, even if that's not it, it's one variable removed.

It just happened to me, today. I swapped both relays (new ones tomorrow), check inertia button in trunk.(will jumper and check voltage tomorrow). Disconnected battery for a while. No rapid flashing of the PATS light. Tried a different key,. don't hear the pump. Bad fuel pump on a car with only 45K ?. Tank is full of gas I'll have fun pumping that out to change the pump.

SOLVED!!! It turned out to be a broken wire in the harness!!! The wiring harness had been rubbing on the frame and just by chance rubbed through the wire that fed 12 volts from the fuse block in the engine compartment0 to the pump. The location is right underneath the left turn signal but can be seen when under the car ( see pictures ). Once spliced back together, all worked perfectly. I am sure there are other cars out there with the same issue... just a matter of time!!! Blue wire with pink tracer. The picture shows where I unwrapped the harness and exposed the wire in preparation for a splice. Could only attach one image... Hope this helps someone else. Took me ALL day to pin point.

Good job, glad it is fixed and happy that you posted the results here.

I have the same problem with an 04 mercury grand marquis some of my engine wiring harness wires got messed up from a bullet that hot my car I had the wires respliced car is turning I’ve but won’t start sprayed starter fluid in carborator start u and shut right back off and when I turn my key forward the anti theft light blinks rapidly

It's your theft system that's preventing your car from getting fuel. I don't know much about those systems, i don't have one. People on here do, though. Try googleing it, there may be info