HI, THE FUSE IN CIRCUIT #5 IS BLWNG EACH AND EVERY TIME i REPLACE IT. MY MECHANIC DOES NOT SEEM TO KNOW WHAT TO DO. IT IS AFFECTING MY RADIO AND POWER LOCKS. ALSO IT KEEPS SAYING MY TRUCK IS OPEN. I PUTA 25 FUSE IN ITS PLACE AND IT WORKED DFOR 3 DAYS BUT IT TAKES A 10. PLEAWE TELL ME WHAT TO DO AND HOW MUCH WILL THIS COST ME TO REPAIR? THANK YOU SO MUCH FOR YOUR ATTWNTION TO THIS ISSUE. I AM AN OLDER WOMAN SO I THINK I AM BEING TAKEN ADVANTAGE OF. PLEASE HELP!
Hi Beverly, That fuse #5 is also called the ignition off draw fuse and it powers up about a dozen and a half lights, locks, and preset memories all over the car which don't require the ignition to be in the run position for power. If you can possibly identify any behavior (i.e. what did you try to activate at the exact time the fuse blows) or that is going 'on' when the fuse blows that would be the best clue. The other approach would be to put a digital readout ohmmeter on the cold side of that fuse socket and see how much resistance it shows with all the door closed and nothing else going on inside. Then you could try turning on each of the lights/devices to see if one causes significant reduction in the resistance, down to 1 ohm or less, which is the point where the fuse blows. Here is a list of all the possible devices to activate/de-activate while reading the ohmmeter: rear floor courtesy lamps, door courtesy lamps, overhead map lamps, visor vanity lamps, glove box lamp, trunk lamp; power antenna, radio memory, power amp for radio (if equipped), key-in lamp on steering column, Traveller device, body control module (separate it from the fuse box to test), the manual power door lock switches, and the left power door lock motor.
Usually a fuse will blow if a lamp bulb has an internal short circuit to ground, so try to find one of the many lamps that I listed above that doesn't work even though you have a working 25 amp fuse in place so that everything is supposed to work: this would be the first thing to try without having the help of your mechanic or needing an ohmmeter to do the measurements. Remove that bulb and see whether that solves the problem. You would do well to start at the trunk lamp and see if that is working because it is in the same circuit as the trunk ajar switch which you said the warning light is showing up on your instrument cluster. If that bulb or its socket, or its wires were shorting out I can imagine that it would blow the fuse and also light the warning light. Take the trunk lamp bulb out of its socket and then see if that solves the problem of the IOD fuse blowing. I hope you can fix this yourself, but if not show it to the mechanic. Please 'rate' my answer (see below). Thanks,