Question on tracking down a short - How to?

[skyguy]

Question on tracking down a short - How to? SOLVED!

Friend of mine has asked me to help him track down a short in his electrical system this weekend. (SOB) Basically, his bedroom lights are out. Fuse blown. Replaced the fuse, popped again right away.

Strange thing is, he was parked in the same place for a couple weeks before this started happening.

Suggestions on how to find the short??

Al S.

 

[Jimmy]

First remove bulbs to make sure one has not blown and shorted, if that fails unhook switch to see if switch is shorted or bare wires are touching each other, if that fails try unhooking each fixture one at a time to locate the problem. If these don't work, get back with us.

 

[wdk450]

Skyguy:
1) Remove all lightbulbs (loads) from the circuit.
2) With the power disconnected (blown fuse) connect an audible (annoying) continuity meter (most DVM's have this function) between the load side of the fuse (or the wire immediately connected to that) and ground using clip connections. With your short still in place the continuity meter will buzz continously. I would go to the lamp base nearest the fusebox and disconnect or cut the wire to break the circuit. You can repair the cut after troulbleshooting is done. If the buzzer stops buzzing, then your problem is beyond your cut wire point. If the buzzing continues, your problems is before the cut wire point. Continue this process of dividing and conquering until you find the bad spot, if you can. Many professionals end up running a new wire to a measured good point in a circuit.
Good luck!!!

 

[porthole]

Pull the light assembly off and check it. There is a good chance of a short with the way they are made/installed.

 

[skyguy]

Thanks all - looks like I will be busy this weekend!

Al

 

[skyguy]

Problem solved! The "pull all the light bulbs" trick helped a lot. Turned out to be an issue with the bathroom fan (same circuit). Run the fan, blow the fuse. Make sure the fan switch is OFF, circuit is fine.

Thanks all - got to love this forum, it is a tremendous resource.