20 Most Recent 2003 Ford Mustang - Page 5 Questions & Answers

Does it sound like its coming from the valve covers ?

Could be the brake switch, or the shift lock solenoid.Both components would need to be tested. And you may be able to shift out of park if you try before you turn the key switch to the on position.

Have the battery checked. A low battery will cause the Antitheft system to kick in. It then reduces starter Voltage resulting in the clicking you report.A bad solenoid Relay will also click. Bypassing the part will allow the starter to work. It will spark, and should not be done too close to the battery. Jumper cables will still spark but more safe to test with for a defective solenoid.

most of the time this is switch problems, again with the ohm/volt meters and wiring diagrams. check for power entering and all the grounds. best i can do for you.
"the only thing that makes a good tech is the directions he follows"
buy a repair manual, these have the wiring diagrams in them and easy to follow.

The check engine light is telling the driver the computer has a problem with something that can affect performance or emissions.The problem is serious when the light is flashing.You would need to have the computer scanned for trouble codes to proceed.

you may need to place the multifunction control module. it controls the alarm,but you need the fob

03 Mustang GT (Parasitic) Battery Drain Fix

Hello, I am seeing a lot of mustangs are having battery draining issues and I wish to share some simple solutions found while working on a friends 03 GT 4.6ltr. In a quiet area, key switched off, hood up, Listen carefully close to alternator. I heard a high pitched hissing/whistle sound at low volume, came from back of alternator. This sound was the voltage regulator/rectifier staying on when key is off due to faulty diodes inside the voltage regulator/rectifier circuit, can cause battery to go dead after car not ran in about 2-7 days. After having the alternator tested free at a parts store, test showed alternator was good because the faulty diodes in the alternator did not show up on the test, the machine did not test for faulty drain back issues that were present. Alternator on-car-fix: There was battery voltage running at all times through the two-wire connector on back of alternator. Disconnect the battery first for safety and to reduce chance of short circuit. The yellow wire/with white stripe is hot while car is off so I traced this from the 2-wire connector on the alternator then closer towards driver side front fender. Next I cut the Yellow/White Stripe wire, spliced a good connection wire to it and ran it through a hole in the fire-wall to the fusebox(under dash), connected it to a 15a fuse that does not get used but has power when key is turned on but no power when key is off. The purpose for re-routing the hot wire to the alternator, is to turn off the alternator charging circuit when the key is turned off so it may not run down the battery. I am seeing good results with this fix(or patch) so far. No More Parasitic Battery Drain! Another fix can be to change the small pulley on the alternator to a larger pulley so the alternator does not spin too fast, putting too much energy through the diodes can cause a charging system to act a fool. So if you have charging issues and have an alternator changed, putting a larger pulley on can make sense turn into saved dollars(especially on high revving engines). I hope this info helps to solve some draining battery and/or alternator issues. for reading, TyBorg1

its possible its the fuel pump it self if u dont smell gas. When u turn the ignnition if u do not hear the fuel pump engage thats the problem. Dont start the car just turn the ignition;.

Well, based on what you are asking.....you need to have the alternator, battery and charging system checked. Most places do it for free. Seems you have a bad alternator, but a service garage should show you exactly what's happening.

sounds like your dome light switch is bad. it is in the door jam. thet wear out ,and act like the door is open when it is closed