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This Escort has a 2.0 4-Cylinder/Auto., and the owner suspected a bad fuel pump. Fuel pump tests fine, the inertia switch is fine, and we're getting power to the injector head, but the 30amp FI Fuse keeps popping. Anyone know where the fuel pump relay is on this application, or what else might be causing this? We're looking for the circuit grounding out somewhere, but no luck. Any good ideas?

DARRAH wrote:This Escort has a 2.0 4-Cylinder/Auto., and the owner suspected a bad fuel pump. Fuel pump tests fine, the inertia switch is fine, and we're getting power to the injector head, but the 30amp FI Fuse keeps popping. Anyone know where the fuel pump relay is on this application, or what else might be causing this? We're looking for the circuit grounding out somewhere, but no luck. Any good ideas?

Good morning.

I believe the fuel pump relay on this one is also called the Constant Control Relay Module. It is located in the LF area of the engine compartment near the back of the headlamp. The PCM grounds the control side of the relay and it looks as though the feed goes through the inertia switch and to the pump. One note: there is a fuel pump diode on this....if it were to fail, it could cause a short.

Good luck.

Had a mid 90s escort one time that the left rear upper strut mount was torn loose from the body and was pinching the harness that runs over it, I think the fuel pump wires are in this harness, not sure though. The car had no symptoms of a messed up srtut mount(noise, rattles, bumping, ect). Might be worth looking into.

Also, is it the Injector fuse or the fuel pump fuse? The FI fuse is known to blow when there is a shorted alternator. Seen a few bad alternators.

Thanks for the replies! Checked the alternator, which seems fine. Wiring harness and inertia switch (bypassed) has no effect. The fuse says 30AMP / FI. Every time the key is turned to the on position, it pops the fuse. Located the CCRM, and my tech is attemping to test it. Any advice on that? I'm tempted to get another one, and put it in, just to quickly condemn or eliminate it. Your advice is greatly appreciated!

DARRAH

DARRAH wrote:Thanks for the replies! Checked the alternator, which seems fine. Wiring harness and inertia switch (bypassed) has no effect. The fuse says 30AMP / FI. Every time the key is turned to the on position, it pops the fuse. Located the CCRM, and my tech is attemping to test it. Any advice on that? I'm tempted to get another one, and put it in, just to quickly condemn or eliminate it. Your advice is greatly appreciated!

DARRAH

If it's the FI fuse, the the pump and assoiciated parts are out of the picture. The Fuel Pump fuse powers them. Unplug the alternator just to be sure it's not the cause. Then unplug the CCRM and see if it's the cause.

Also, the FI fuse powers all the injectors and the IAC. Be sure to check those and the associated harnesses. Additionally, it powers the MAF, the rear o2 heater (very common) and the evap purge and purge sensor. All are suspect.

Thanks, everyone! As it turns out, it was two issues causing the problem, both of which have been mentioned here. The alternator diode was not functioning properly, and we believe it caused a ground wire short elsewhere.

Your help is priceless...thanks!

thanks for posting the fix. now i have to ask where "elsewhere" is? if there is a shorted ground or short to ground it must be found. I'm pretty confident the alternator was the issue and the car is fixed because of the well known internal shorting issues but i would scan all the sensors using the bar graph option to easily see any inconsistencies. i have to add a welcome to the forum and thanks for following through.

No. In this case, the customer was the cause...

An aftermarket product he wired into a harness caused a short, which caused the problem with the fuse blowing. Customer was embarassed, but happy to pay the diag time to have his solution...

another perfect example of sitting a customer down under a spot light and grilling them about anything they either did or had done before this issue arose.

You've got that right, Steven!