keep blowing blinker bulbs

[Brendan-s]

ok forgive a n00b question please but i keep blowing out the bulb in my right fender blinker. its been happening for about a week now. within a day of a new one put in it'll blow, the last time it lasted 2 flashes

i dont know much about electrics but i figure it's shorting out somewhere. my question is what should i look for, i.e. bare wires etc?

Thanks in advance

Brendan

[-Scott-]

Please assure me you're not putting 12V globes in a 24V system.

Scott

[Vulcanised]

sounds like a bad earth or a dead short somewhere near the blinker

[Modified Toy]

the globe holder itself could be rusty causing a short wurth a look.

[jeep97tj]

You could have a bad short on the earth side of your globe so it is drawing to much power and the globe is blowing like a fuse.
The best way to find shorts in a harness is to replace the fuse ,or in your case the globe with a thermal circuit breaker, then u follow along the harness with one of thoses needle amp guages that u just sit on the wire to get a reading.
Follow along the harness, between the now circuit breaker and the short, u will have a amp reading, it will go up and down as the circuit breaker clicks in and out. After the short u will get no reading at all (or very little), and between the 2 u should be able to locate it. If u are getting a amp reading all the time u might have power in another circuit, if u cant turn it off u will have to disconect the + terminal and then run a jumper wire from the + terminal on the battery to your circuit breaker.

Have fun

[GOT MUD]

i had this problem in my rodeo it turned out to a spare trailer cable running along the chassis rail that was earthing the indicator wire out on the fuel tank

[dumbdunce]

um, please explain how a bad earth or a short circuit could blow a light globe?? the voltage across the globe can't possibly be any higher than the system voltage - a short will cause 0v or 12v at the globe, a bad earth may cause wierd low voltages across any number of globes but it can't cause over voltage.

actual possibilities:

1. your charging system is dysfunctional and is generating a too high voltage. test the voltage with a multimeter across the battery with the engine at 2000rpm, voltage should be between 13.5 and 14.5V.

2. 12v globe in 24v system (or 6v glove in 12v system)

3. you're using crappy Narva (or other trashy supercheap auto brand) globes

4. you're using too high a power globe and it's overheating in the holder (unlikely, most corner indicators use 21W globes).

5. highly unlikely but possible, the light assembly is vibrating and causing premature failure of the filament

6. eveyone sit back and have a cold, refreshing #6.

7. (most likely) it's solar flares reversing the quintuxulated neutrino flow in the flasher relay, you need to wrap your entire car in alfoil and wear an armadillo skin helmet to deflect the rays and the problem will go away.


cheers

DD

[pongo]

I dont know how to explain it but it can happen. I think that maybe its the golbe wattage is lover than the fuse ampage, so that might make the globe a weak point. Ive had it happen before, But cant explain it.

Bad earths can do all sorts of weird and wonderfull things.

[dumbdunce]

I dont know how to explain it but it can happen. I think that maybe its the golbe wattage is lover than the fuse ampage, so that might make the globe a weak point. Ive had it happen before, But cant explain it.

for a globe to blow, it has to flow more current than it is designed to flow. To flow that excess current, it must be exposed to excess voltage. Since vehicle globes are already exposed to full system voltage, it's not possible to generate excessive currents in them by means of a short circuit.

Bad earths can do all sorts of weird and wonderfull things.

agreed - but they don't blow globes, just make them glow dimly and come on at the wrong time.

I still say it's solar flares. that or the damn aliens.

[Bluey]

I dont know how to explain it but it can happen. I think that maybe its the golbe wattage is lover than the fuse ampage, so that might make the globe a weak point. Ive had it happen before, But cant explain it.

for a globe to blow, it has to flow more current than it is designed to flow. To flow that excess current, it must be exposed to excess voltage. Since vehicle globes are already exposed to full system voltage, it's not possible to generate excessive currents in them by means of a short circuit.

Bad earths can do all sorts of weird and wonderfull things.

agreed - but they don't blow globes, just make them glow dimly and come on at the wrong time.

I still say it's solar flares. that or the damn aliens.

current can be increased simply by decreasing the circuit resistance (like a short to ground) as volts=current * resistance. the only way i can think this could blow a globe though is if the short is after the globe, and the current has to flow through the globe to get to the short. of course this would only happen if the fuse isn't working properly to protect the circuit (to high rating or slow blow type), and i don't think any blinker is wired up like this anyway

if this was the cause of the globes blowing then i reckon they would glow brighter than normal condition before blowing because a greater current is flowing through them


or it could be the solar flares




Lance

[Brendan-s]

Please assure me you're not putting 12V globes in a 24V system.

Scott

lol nope i aint THAT dumb *shifty eyes*

but hang on... i've been using narva globes assuming that they were at least as alright as their spotties? hmm after i try everyone's suggestions i will go buy a decent pair

[dumbdunce]

Please assure me you're not putting 12V globes in a 24V system.

Scott

lol nope i aint THAT dumb *shifty eyes*

but hang on... i've been using narva globes assuming that they were at least as alright as their spotties? hmm after i try everyone's suggestions i will go buy a decent pair

if it's the narva globes yo owe me an armadillo helmet!

[-Scott-]

current can be increased simply by decreasing the circuit resistance (like a short to ground) as volts=current * resistance. the only way i can think this could blow a globe though is if the short is after the globe, and the current has to flow through the globe to get to the short.

Dude

Globe circuit: +V -> (bulb) -> gnd.

One side of bulb directly connected (i.e. shorted) to +V, other side directly connected (i.e. shorted) to gnd.

As dd moentioned, the only way you can put too much current through the globe is if there's more voltage than it's designed to handle. Dud regulator, voltage mismatch, or plain crappy design.

Scott

[MQ080]

I still say it's solar flares.

This may also be the cause on why people back off when going up hills

[Hekta]

Change your blinker fluid

[Bluey]

current can be increased simply by decreasing the circuit resistance (like a short to ground) as volts=current * resistance. the only way i can think this could blow a globe though is if the short is after the globe, and the current has to flow through the globe to get to the short.

Dude

Globe circuit: +V -> (bulb) -> gnd.

One side of bulb directly connected (i.e. shorted) to +V, other side directly connected (i.e. shorted) to gnd.

As dd moentioned, the only way you can put too much current through the globe is if there's more voltage than it's designed to handle. Dud regulator, voltage mismatch, or plain crappy design.

Scott

was thinking more of a series circuit where there would be more globes in the circuit. for a 2 globe circuit, and if the short is between 2 globes for instance, then the high current would flow through first globe before it gets to the short. thinking about this tho it should just keep the globe (ist one) on continously (as there is 12v one side and gnd the other) , and the globe filament would limit the current

this wiring setup would be highly unlikely in vehicle blinker setup.

err, it think that's it. a wiring short shouldn't cause any globe to blow