Electrical Help Needed Please!!

[gravel]

Ive just installed a 55 watt Hella worklight on the rear of my Hilux.

I was hoping that it might be a bit brighter so am thinking of putting a 100 watt globe in it instead.

It is a glass fronted light. Will the 100 watt globe burn out the internal fittings of the light or would it be ok?

Cheers.

[BadMav]

What size wiring are you running to it? What's the earth like? Are you running it through a relay?

[coxy321]

What size wiring are you running to it? What's the earth like? Are you running it through a relay?

Spot on!

- Minimum 3mm twin wires (earth back to battery, not chassis)
- 40A relay
- waterproof fuse holder or circuit breaker

Make sure you run your 3mm twin in conduit too - don't want and chaffing.

[dillza_69]

What size wiring are you running to it? What's the earth like? Are you running it through a relay?

Spot on!

- Minimum 3mm twin wires (earth back to battery, not chassis)
- 40A relay
- waterproof fuse holder or circuit breaker

Make sure you run your 3mm twin in conduit too - don't want and chaffing.

100W @ 12v is 8.3A no need for 40A relay (anything rated above 20A would be more than enough) or for the negative to be run back to the battery. Providing he uses appropriate lugs and an appropriate connection to the chassis it would provide a greater current carrying capacity than 3mm cable as it would have a far geater cross sectional area.

The only justification i could see for 3mm cable would be to negate voltage drop.

[coxy321]

Force of habit for me - i buy relays by the case, and wire by the roll.

[fazza81]

even though the light is glass front still be careful of the extra heat from the globe can still crack the glass if left for extend periods.

[PacMan]

On the Hella webpage should be infos about the max lamp size.
And if there is no info, just try it. If the plastic in the back gets very hot, change it back.

earth back to battery, not chassis

I never understood why people run the negative to the battery - maybe they like a lot of cables on the battery plus and minus...
A winch is the only exception.

[howsie]

On the Hella webpage should be infos about the max lamp size.
And if there is no info, just try it. If the plastic in the back gets very hot, change it back.

earth back to battery, not chassis

I never understood why people run the negative to the battery - maybe they like a lot of cables on the battery plus and minus...
A winch is the only exception.

id have thought since batterys earth to chassis anyway the earth would be just as good if not better than at the battery

[festy]

Not all chassis are earthed!
Use the body instead, it's a safer bet.
I agree though, that at the rear of the vehicle earthing via the body would produce the same or less voltage drop than running a wire to the battery (assuming all connections are good).

[brissle]

i like to run the earth to the battery too(or engine bay at least), only because of the dirt and moisture at the chassis can cause problems and I buy wire on the roll as well , twin core can be used for many puposes so generally buy it by the roll and use it for everything

[howsie]

when using heavy gauge or high current wire its not such a problem. But i was always told the shorter earth lead you have the more effective it will be

[Dooley]

Not all chassis are earthed!
Use the body instead, it's a safer bet.
I agree though, that at the rear of the vehicle earthing via the body would produce the same or less voltage drop than running a wire to the battery (assuming all connections are good).

I think you're misunderstanding... chassis in terms of electronics/electrical typically means the body, shell, case etc.

Like with consumer gear the chassis is the enclosure or case, if metal, and may be earthed for safety, depending on how it's powered.

So by chassis it doesn't necessarily mean the actual chassis in a car... if that makes any sense.

[howsie]

Not all chassis are earthed!
Use the body instead, it's a safer bet.
I agree though, that at the rear of the vehicle earthing via the body would produce the same or less voltage drop than running a wire to the battery (assuming all connections are good).

I think you're misunderstanding... chassis in terms of electronics/electrical typically means the body, shell, case etc.

Like with consumer gear the chassis is the enclosure or case, if metal, and may be earthed for safety, depending on how it's powered.

So by chassis it doesn't necessarily mean the actual chassis in a car... if that makes any sense.

i had meant body and such as well but had also assumed all chassis were grounded. You learn something new everyday

[Dooley]

Not all chassis are earthed!
Use the body instead, it's a safer bet.
I agree though, that at the rear of the vehicle earthing via the body would produce the same or less voltage drop than running a wire to the battery (assuming all connections are good).

I think you're misunderstanding... chassis in terms of electronics/electrical typically means the body, shell, case etc.

Like with consumer gear the chassis is the enclosure or case, if metal, and may be earthed for safety, depending on how it's powered.

So by chassis it doesn't necessarily mean the actual chassis in a car... if that makes any sense.

i had meant body and such as well but had also assumed all chassis were grounded. You learn something new everyday

Well that's my take anyway... pretty much everyone says chassis earth even if it's say the body instead. So it's basically just whatever pieces of metal on the car itself will conduct to the negative terminal. That's how I see it, like there's a metal bracket behind the dash when I replaced the stereo, a bolt through that I still call a chassis earth even though it is not the actual chassis itself...

I may be wrong though but that's how I see it at least.

[festy]

Like with consumer gear the chassis is the enclosure or case, if metal, and may be earthed for safety, depending on how it's powered.

Probably not a great example - most(?) consumer appliances are double insulated, so the case/chassis/box shouldn't be earthed - but I get what you meant...

[dillza_69]

Like with consumer gear the chassis is the enclosure or case, if metal, and may be earthed for safety, depending on how it's powered.

Probably not a great example - most(?) consumer appliances are double insulated, so the case/chassis/box shouldn't be earthed - but I get what you meant...

Anything with a conductive outer shell or casing must be earthed ie. not double insulated

[BadMav]

Another thing too, if the chassis is not connected electrically to the body/ battery and you have a high current draw earthing to the chassis it fries the coiled brake lines, boils the fluid and sets the plastic clips on fire. Seriously.