You can't even trust fuses!

[Lazy-Ferret]

My spots were doing something weird last night, like taking a couple of secinds longer to come on after I flicked to main beam. They would then be ok for a few times before doing it again. I made a guess that the joint where I had T'd into the main beam must be bad, and then as if to prove my point they stopped working completely.

Checked them out today only to find the fuse had done this and melted the holder.

I am so glad I over rate all my wires, as everything else was ok. I can only think that the link inside had come loose and was arcing.

sent from my phone, sorry for any typo's.

 

[rustic]

There are a lot of cheap far eastern fuses on the market ...:doh

They have the wrong spec material. at close to full load they get very hot, bearing in mind that the fuse is unlikely to blow at much under twice the marked rating.

At 1.5 or greater load, the fuse itself can get too hot to touch.

I recently re wired my switch panel on the boat, and I tried different loads through the fuse, and the holder also started to get warm, BUT did not melt, so watch out for these cheap fuses.
My holders were rated at 10 amps, so I loaded the 10 amp fuse with 15 amps.

Also check that the fuse to holder connection really grips the fuse.

Potentially this is a fire just waiting to start:doh:doh


Rustic

 

[rustic]

To add to my above post, have a look on this web site...

http://www.sunfuse.com/images/pdf/Fselguide.pdf

Shows what the expected times are for particular fuses, and it could be several seconds for the fuse to blow at 1.5 times load.

The car blade type are not listed, those can be much different.

 

[Banshee]

My spots were doing something weird last night, like taking a couple of secinds longer to come on after I flicked to main beam. They would then be ok for a few times before doing it again. I made a guess that the joint where I had T'd into the main beam must be bad, and then as if to prove my point they stopped working completely.

Checked them out today only to find the fuse had done this and melted the holder.

I am so glad I over rate all my wires, as everything else was ok. I can only think that the link inside had come loose and was arcing.

sent from my phone, sorry for any typo's.

Sounds like you're drawing too much current there mate

I was always told it's illegal to tap into main beam for spots :nenau

 

[Lazy-Ferret]

I did make the mistake of getting some of those cheap ones a while ago, they are fairly easy to tell though, as the blade is a lot thinner, and does not make a good connection when slotted in, ended up throwing them all away.

This one was supposedly "OK" as it was from Halfruads. I spent a while fault finding, and I think the relay had a dodgy internal connection, and was oscillating on and off very fast for a short time before it packed up. I know halogen bulbs draw a high current as they first turn on, so I guess if you switch them on and off very quicky, the current will shoot up.

Sounds like you're drawing too much current there mate

I was always told it's illegal to tap into main beam for spots :nenau

Not drawing too much current, the lamps are 2x55w, so only just under 10amp, the fuse was 20amp, and the cable is all 40amp, so all well within speck.

It's definitely not illegal, to have them switch on and off with the main beam, and if you think about it, a lot of cars come with spots that do that as standard, My Scooby, and all my Volvo's did it. How else are you going to get your spots to come on and off with main beam, with out tapping into the main beam at some point.

 

[AlexD333]

I did make the mistake of getting some of those cheap ones a while ago, they are fairly easy to tell though, as the blade is a lot thinner, and does not make a good connection when slotted in, ended up throwing them all away.

This one was supposedly "OK" as it was from Halfruads. I spent a while fault finding, and I think the relay had a dodgy internal connection, and was oscillating on and off very fast for a short time before it packed up. I know halogen bulbs draw a high current as they first turn on, so I guess if you switch them on and off very quicky, the current will shoot up.



Not drawing too much current, the lamps are 2x55w, so only just under 10amp, the fuse was 20amp, and the cable is all 40amp, so all well within speck.

It's definitely not illegal, to have them switch on and off with the main beam, and if you think about it, a lot of cars come with spots that do that as standard, My Scooby, and all my Volvo's did it. How else are you going to get your spots to come on and off with main beam, with out tapping into the main beam at some point.

Yar, Mr Ferret did mine like this, it's great :thumb2

 

[elty001]

Had spots wired into the main beam on almost every car I have ever owned and never had a problem with the law or mot's :nenau