electrical problem

[alhoffman]

my 99 mgm has developed an electrical problem. it lost power to door locks including key less entry on the door, power mirriors. interior lights, and the auto climate control. i found a blown 15 amp fuse that suplies the lighting control module replaced it and it blew again. i made a test light pluged it in where the fuse goes and the light shows a dead short. removed the auto climate control... and the light stays on still a short some where.... now with the test light in the fuse spot. with the door open the test light stays lit.... when i close the door the test light dims and i buzzing noize starts out soft and starts to get louder as the test light dims..... the buzzing noise seems to be coming from a control with a couple large cables pluged into it,,,,,, could this be the lighting control moduel.

need some help here please AL.

[Crasen]

I am trying to figure out exactly what you are trying to do. Are you trying to test for a short by using a light bulb to see if there is a path to ground at the fuse while everything in the circuit is unplugged. If so make sure you are using a wiring diagram because owners manuals often do not list everything a fuse powers in that circuit. If there is any electrical component still hooked up in the circuit the light will come on and it does not actually indicate a short in the circuit. Another way you could try to find the faulty component if you decide it is not wiring is to unplug everything in the circuit, install a new fuse, and reconnect the components one by one. If you plug a component in and the fuse blows you probably found the culprit.

[alhoffman]

Originally Posted by Crasen

I am trying to figure out exactly what you are trying to do. Are you trying to test for a short by using a light bulb to see if there is a path to ground at the fuse while everything in the circuit is unplugged. If so make sure you are using a wiring diagram because owners manuals often do not list everything a fuse powers in that circuit. If there is any electrical component still hooked up in the circuit the light will come on and it does not actually indicate a short in the circuit. Another way you could try to find the faulty component if you decide it is not wiring is to unplug everything in the circuit, install a new fuse, and reconnect the components one by one. If you plug a component in and the fuse blows you probably found the culprit.

Thank you for the reply.... what i am trying to do is find the short. cir # 8 blows fuse.. i was told to plug test lite in place of fuse and start disconnecting everything on that cir till i find the culprit. dont know if it is in the harness wires or a device. or controler.... with the key off should you not have voltage across the fuse slot with the fuse out?or should i test from each side of fuse to ground.... i have wireing diagrams and one thing on the circuit i havent tried is the key pad on the door. i have to remove the door panel to get to the connector.... any help would be graeatly thankful.....

AL

[Crasen]

Ok I get what you are saying. If you have every component the circuit powers disconnected and you place the test light across the fuse slot and the light comes on it will indicate a short to ground because there should be no paths to ground with everything disconnected. which would indicate a wiring problem. However if anything is still connected the light will come on when that component completes the ground. Which is why your light came on when door opened. I understand why you wouldn't want to pul the door panel if you can avoid it. I would look for a connector going to the doors wiring harness, no connector I would even consider cutting the wirings for troubleshooting if they are easy to get to, cutting the wires and taping them up would do the same as disconnecting them and might be easier than removing door panel, depending on good you are at wire repair. I would not worry if you should get voltage to the fuse or not with the key on, it would not cause the fuse to blow. The fuse will blow becuase you have too much amperage going throught the fuse, this can be caused by a component drawing too much elecricity or by a short in the wires after the fuse, so your problem i s after the fuse