off road lights

[arrabil]

10 seconds until the fuse blew means something is wired wrong. If its wired right and blows the fuse (due to overload) it will blow it instantly. I wonder if there is still a bad connection but a really fat wire in the loop absorbing the current overload. Do any of the wires feel hot? Any of them much bigger than the others? Could be a loose short that needs to be wiggled to make contact.

I would start from scratch....

 

[Willl]

still a bad connection

I'm thinking same.

 

[kebo]

100W at 12 volts is only 8.3 amps/light. A 40amp relay and a 40amp fuse (with the correct wire) would handle 4-5 lights no problem (and leave you with a smaller wire and a lighter switch in the cab.
You should at very least put a fuse within 6" of the battery. It would be a shame if the wire wears through, shorts, overheats and burns down your truck just for the lack of $7 worth of fuses and a fuseblock.

Socket: Amazon.com: 12 VDC 5-PIN RELAY SOCKET: Electronics
Relay: Amazon.com: 12 VDC Waterproof Relay SPDT 30/40A with Metal?/url]
Fuse Block: [url=http://www.amazon.com/line-ACT-Water-resistant-Fuse-Holder/dp/B0002KR88A]Amazon.com: In-line ACT Water-resistant Fuse Holder - 10 AWG:?/url]

Aaron Z

Your thinking is correct, but you left out the inrush current factor. If all 4-5 lights come on simultaneously the initial current draw will probably be over the 40 amp fuse rating. Depending on what type of fuse (slo-blo, fast-blo, time delay, etc) it may or may not blow the fuse. Thats why in electricity/electronics you typically over design for this sort of thing and leave yourself a comfortable margin. The end result is the protection device (fuse) should be the weakest link, and the first thing to go.

 

[Tul01]

Thanks for the quick responses guys, the fuse is within 6" of the battery, I will look at the switch end next. I didn't notice anything getting hot when I was over helping. The new wires at the light end are 14g, maybe I will have a closer look at the wiring running to the switch, I knew the wiring was bad to the lights as it fell apart and I could see corrosion so I just assumed that was the problem. thanks again
Brent