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Chuck, ASE Certified Technician
Category: Mercury
Satisfied Customers: 2101
Experience:  33 Years experience,Ford Senior Master,ASE Master,L1 Advanced Engine Performance
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Mercury Cougar Is there a emergency fuel shut off switch,

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Is there a emergency fuel shut off switch, or if I suspect my fuel pump is out, what are the steps I should take first before I drop the tank and replace it. The fuel pump is accesable from the rear seat area interior if a test can be made.

Chuck :

The fuel shut off switch is located behind the left kick panel.You need to make sure you have power on both wires.Here is a copy of the wiring schematic to help you.

Chuck :

If you do not have power to it then you will need to go to the under hood fuse panel and check the 2 fuses indicated in the schematic.No.41 and no.9.

Chuck :

If these are ok the you will need to check the relay.How it works is on the coil side pin 15 in the schematic. POwer is supplied to the coil and when you ground it then this energizes the coil which creates a magnetic filed and pulls the switch closed so power on pin 30 can then flow to the interia switch and then to the fuel pump driver module.

Chuck :

Here is a pic of the fuel pump driver module it is located in the rear quarter panel drivers side.

Chuck :

Now to test the pump if you have power all the way to the fuel pump driver mosule just go to the pump and put power to the white/black wire and ground on the brown/yellow and the pump should run. If it does not then it is bad.

Customer: replied 6 years ago.

Chuck, you are very clear and I can not tell you how easy you are making this for me. So looked at switch in drivers side kick plate and not tripped but no power, checked in fuse block and this is what I found.

F1 should be 20A (missing)

F39 " 60A ( " )

F40 " 20A (blown )

F41 " 20A (blown )

F42thru45 normal

next row over F14 should be 7.5? Missing? sent for fuses, I assume I should procede as you already explained, and will unless you advise otherwise. You Rock!

F1 and F39 are not used


F40 is to the ignition and the headlight switch

F41 is to the fuel pump relay and the PCM relay.


I suspect that you have a short somewhere.I am afraid as soon as you replace these fuses they will blow again.


Since This is the coil side of the fuel pump relay I would not suspect a problem with the fuel pump,if it was fuse 9 blowing which is the switch side then I would suspect the pump.


Let me know if they blow again and we will try and figure out how to find the problem.

Customer: replied 6 years ago.

OK Budd, I have power to the ignition coil, I have spark on spark plugs, I have replaced number 40&41 fuses (these two where blown when I first looked at car) After your first reply and excellent directions of the inertia switch etc, I checked the inertia switch and "I dont think it was blown"? the red button on top was DOWN I kept messing with it before I did any thing and got it to pop up. After reading owners manual found that the working position was to depress the red button and did so. I have even jumped across the switch with a jumper wire and a 5A fuse and have no problems, no fuses have popped while testing, while key was on, or while trying to start the engine. I even believe I may have smeled fuel once? Not sure though.

So All fuses are in and good, spark to cylinders is being provided, and have power going thru the enertia switch to the Fuel pump driver. I am now going to try to figure out how to get to the fuel pump driver on the rear quarter, and I tried to get a Chiltons manual for it at the parts store and was advised they dont make one yet? So any advice how to test the pump driver would be great! Your info on how to test the pump it's self was Awsome.

Just go to the pump first,that will be easier. Looking at the schematic I sent you on the pump check for power on the white/black wire when you cycle key on.Now you will only have it for about 2 seconds before it cycles off so you will need some body to cycle the key on and off while you check it. Also check the ground on the brown/yellow wire.


You can also get you a couple of jumper wires and a battery and disconnect the pump and put power on the W/BK wire and ground on the BN/YE wire and see if the pump will manually run then.


Chuck and 2 other Mercury Specialists are ready to help you
Customer: replied 6 years ago.

OK on the Cougar, I tested for volts at the pump switch, by unconnecting the plug from the pump, Key on or off NO power. Cranking motor, NO power. Plugged back in to pump and tested by pushing probes into wire insulation, after about five tests w/key on/off & cranking, one time got a glimps of a volt or two for a half a second. Went back to the wire connector that connects to the inertia switch, at that point I am wondering. How do I make sure I'm checking that switch correctly?

What I have done is try to use the voltage meter on 12v popped the 15A #9 fuse under hood. tried with a probe light that has two little lights on it ( one - and one +) tested on batery first and it worked perfect three tries. made sure fuse was good and tested the two black lines going into inertia switch and it popped two times. Please advise how I test for power to the inertia switch? and Please advise if testing the inertia switch with a probe test light should pop the # XXXXX fuse?

No the voltmeter or probe shouldn't blow this fuse.What does it do if you unplug the pump and test for voltage at the inertia switch?
Customer: replied 6 years ago.
OK one last question charged batery up all night on trickle, Have not tried to crank moter more than 35-40 seconds total! and its about dead! Also I tested the connection at the pump with key in the ON position I get 0.13 volts when I crank the moter I get no more than 9.5 volts durring cranking but no fuses are popping. So I guess my questions now are, (1) if the battery was low and I'm clear this battery is junk! could that keep the pump from running? and (2) would only having 9.5 or less volts at the pump stop it from running?

Yes a weak battery with only 9.5 volts to the pump can keep it from running.


I am still concerned about the 2 blown fuses though especially since they were on the coil side of the fuel pump relay.I have a strange feeling you have a wire shorting to ground that is on the power side of the EEC relay.

Customer: replied 6 years ago.
What is the EEC? and if I go get a new battery and try it, well I guess what I'm saying is I have to have a new battery no matter what right? so..I'll get back to ya after I put a new on in and let ya know what happens, Please advise if I should not try it?

The electronic engine control relay.


Yes install the new battery and see if you get the 12 volts to pump and see if it starts.

Then get back with me if you still have problems,especially if it blows a fuse again.

Customer: replied 6 years ago.
Chuck! Help? I've, Installed battery after having it tested by two shops they both said it was good? I checked the pump connection and when ignition is in crank position I do get 12v for a second, tried over and over again and it is there each time I try it. I have not had any fuses blow after any check or test. SIDE NOTE: when I did get a blown fuse the other day? I was putting the Ground side of my multi tester on a ground and touching the hot wire going to the Emergence shut off switch! after I stopped doing that silly thing, it stopped popping! So I have spark on the pulgs I have a good emergency switch and I have power to the pump for a second when cranking motor. have not touched the Fuel pump driver module yet, but the wires that connect to the pump connector when I test it with key to the ON position I only get like 2volts? so to be clear, I test the wt-blk/brn-ylo wires feeding the pump it has a connector with three lines or connectors on the bottom row R is blk/white Middle is black L is brn/ylo ,,,,,then on top of that is smaller like 18/22 gauge wires black/white and a nother ?ground I guess they go to the driver module? if I test those iether before or after I test the pump for power I get about 2v there with key on. What do ya think? I have not! tested pump with direct power yet, just to let ya know

Ok check it with key in on position,not start.When you turn the key to on position pump should come on and run for about 2seconds. You should have power on the white/black wire on pin 3 of the connector at the pump.Pin 1 the brown/yellow wire is the ground.

Here is a pic of the connector at the pump.




Chuck and 2 other Mercury Specialists are ready to help you
You will only have power there for about 2 seconds when key is turned to on position
Chuck and 2 other Mercury Specialists are ready to help you
Customer: replied 6 years ago.
OK with key on I get power to the correct pin on that switch for a second or two just like you said I would. But when crank motor does not seem to get fuel, Yes I have fuel, he,haw!
So did you get it started?
Customer: replied 6 years ago.
Nope. I'm sorry Yes I have fuel, comment was meant to say yes I have fuel in the tank...Sorry Chuck. I have not got fuel to come up to the motor yet? should the Fuel pump driver module be replaced or checked? only thing I have not touched yet? car is in perfect shape in and out and under hood? just over 100k? but I have no idea how previous owner was about maintenance.

I thought you said you had power to the pump for the 2 seconds when you turn the key to run? That means the fuel pump driver should be working.Does the pump actually run when you get power to it?

Customer: replied 6 years ago.
Your correct I did say that and I do have power to it, so I guess I need to test the pump now with power dirctly applied to the 3 blk/white and ground to the 1 brn/ylw I'm on it! I was hoping it was not the pump, but hey thanks for all your help. so at this point if I put power to it, and no gas to car gotta drop tank and replace ya?

Yes the manual states to drop the tank to replace it.However if you have a return system I have seen guys remove that one without dropping the tank just remove the rear seat and the grommet.You can then use a screw driver and hammer to remove the ring and then the pump.

If it is the returnless system it takes a special tool to remove the retainer on it.



Customer: replied 6 years ago.
OK I tested the pump with power directly from the battery, No pumping fuel, so I assume I am replacing a fuel pump? It sems it was changed in 2004 the pump is a Ford Motorcraft and it has a sticker dating it to then. Looks like it has a regular old ring that spins off like most and that it just spins off. I surley have room to do this thru the access hole under seats, can you tell me how I know if I have to use a special tool or not?

Looking at this pic see the fuel rail in the pic no.7 is a returnless system and no.6 is the return system.




ItemPart NumberDescription
1 - Fuel injection wiring harness
2 - Fuel injector
3 - Fuel pressure relief valve
4 - Throttle body
5 - Fuel pressure regulator
6 - Supply manifold (vehicles without returnless fuel system)
7 - Supply manifold (vehicles with returnless fuel system)


I have circled in red what you will need to look at. If you have the 2 lines then this is the one that you can get out without a special tool although they show using a special tool on it also.







Customer: replied 6 years ago.
Chuck, looks like I can get the pump, so I am going to do this now, I have a fuel line intering the pump that has a plastic cover? over it can you give me an idea of how to remove this line? Is there a tool I need? I can not find a manual for this car so I'm really at a loss. Any tips? I am jacking up the car and putting it on blocks because I assume I have to drop the tank?thanks

If yours looks like this you should be able to squeeze the 2 tabs indicated in this pic and disconnect it.



Chuck and 2 other Mercury Specialists are ready to help you
Customer: replied 6 years ago.

Chuck the pump is the Ford fuel pump it sticks up above the tank aroug one and a half inches and has one line coming out forward, and next to it also facing forward is the connector. I can get the retaining ring off while tank is still on car by accessing thru the hole in the floor board. But I assume the pump will have to be removed by dropping the tank? I went and seen this pump at Ford it is the only one I've seen that seems to be the right one.

Yeah the shop manual states to drop the tank.But if you can get that line off from the top I would try and see if it will come up thru the hole before dropping it.It would sure be worth a look.


What may be case is the angle you have to turn the pump to get it out of the tank. There is a guy at our shop that has removed them without dropping the tank,I think he bents the hole up some to get clearance then taps it back down with a ball pin hammer when he is done.But I haven't actually watched him do it so I can't say for sure.