Clearance light causing a short?

[grantgoold]

Has anyone had the experience of a clearance light bulb causing a short in the system? I am going to rehab all the lights in the coming weeks and was hoping that my short tripping of the breaker is just a sign that one of the two burnt out bulbs is actually shorting the system.

Anyone?

Thanks

Grant

[JackConrad]

Grant,
   Anything is possible, but I have never seen a burned out bulb cause a short. When the bulb element burns out out this creates an "open" where no power is flowing through the bulb.  I would be more inclined to suspect a wire that is chafed and touching the frame somewhere.  Jack

[grantgoold]

Thanks Jack! I guess I was hoping against hope that I do not have to start thinking about how I am going find and replace that wire?

Grant

[JackConrad]

Grant,
   If I remember correctly, there are several wires conected the the marker light terminal in the front panel. I would disconnect all of them and reconnect them one at a time until you find the guilty one. This will at least narrow it down.  Have you installed anything with screws since they were working properly?  Maybe you hit a wire with a screw (Dont' ask how I know this can happen!)  Jack

[grantgoold]

Jack, it is sooo good to know that I am committing the same errors! Do not ask me how I know. I will do exactly as you have suggested.

Thanks again for your help.

Regards,

Grant

[FloridaCliff]

Grant,

That is the same reason I ALWAYS start the bus after a days of work on it. Even if I am not messing with anything that shouldn't affect its operation.

Knocked a wire loose once and took me days to find it, I had accidentally hit it (it had a bad connection anyway) but did not move the bus for almost a month.  Finally backtracked that day to everywhere I was.

Anyway, Hasn't happend since, but I still check....

Cliff

[FloridaCliff]

Grant,

A corroded socket could cause that short, just use the Ole "Conquer and Divide" method (as Jack described) and you will have it fixed in no time.

Cliff

[NJT 5573]

Check the lenses for water.

[Stormcloud]

I had a turnsignal bulb short internally and caused the breaker in the bus to trip out whenever I signalled a left turn.

New bulb (less than 2 weeks of use) in a new socket, totally dry and wired correctly...I have never had a bulb fail like that ever before...another new bulb in the socket cured the problem.

I guess theres a first time for everything.

HTH

Mark

[Chopper Scott]

Actually Stormcloud I also had a bulb causing a short once myself. It was on a car but changing the offending bulb cured the blown fuses so it's not impossible. One other thing to consider Grant. I have found offending connections on motorcycles causing problems by observing them at night when it is really dark. You would be surprised at the glow you can see and I would imagine 24 volts would give you even a better spark. Check for any kind of warmth in the wires if possible also. I know the buses wiring isn't as exposed but just another idea. Electrical problems can drive a sane man to buy a bus!!!   Later

[eddieboy]

Usually, when a bulb burns out, it does open.  On occasion, the filament can wiggle around from vibration and arc, and reconnect itself.  At this point, there is less filament and less resistance.  The filament is shorter than it originally was. Thus the term "short".   This causes the circuit to draw more amperage.  A tell-tale sign is that the bulb will usually be much brighter than normal.(if the breaker or fuse can handle it)  It will also burn out a lot faster if you can keep power on it.  I am not suggesting that you put a bigger fuse in or anything like that.  That could create too much heat and maybe a fire.  Of course, all incandecent bulbs will read as a shorted when checking with an ohm meter.  Good luck.  Ed