Cigerette Lighter/Fuse rating

[POSBORNE]

I've bought one a portable fan/heater unit from motorworld for my discovery 1 200tdi, 1991 (h reg). It requires a 15Amp fuse to protect it, as per the instruction leaflet. but the Disco's cigerette lighter (which it plug's into) is only protected by a 10Amp fuse, which i've blown twice using this unit.
On returning to the shop, the sales rep said that you just need to replace the fuse with the 15Amp fuse, and it will work. But that sounds abit dubious to me, as land rover wouldn`t of designed the circuit for the cigerette lighter to be protected by a 10Amp fuse, then for customers to replace them for a higher one. As i don`t know whether there is spare capacity on the wiring loom for this extra capacity. I don`t want the wiring loom to suddenly go up in smoke!

The unit is a 150w unit from Ring, and there is nothing else being powered off this circuit bar the cigereet lighter.

thanks

[Disco Matt]

Given the size of wiring LR used I wouldn't uprate the fuse! You could easily fit a second socket with a 15a rating though, you'd just need to work out where to put it. I added one in my boot to run a flashing beacon or indeed anything else that can plug into it. It's controlled by a small switch added to the dash, so can be operated independently of the ignition.

[Mud_Medic]

Hi Posborne

You are right to be worried. I don't know how good the wiring is in a Disco I, but I would not increase the fuse. The fuse is there to protect the wiring... If you draw too much current, the fuse blows rather than the wiring smoking!

The only way to be sure is to run a new line from the battery. That way you can use cable rated at something like 18a, and fuse it at 15A. That way you won't set anythink on fire.

Also 150W is not a lot of heat, may be useful to demist the windscreen, but it won't warm up the inside of the vehicle any significant amount. (it will take 7 of these to be the same as a 1 bar electric fire!)

Ed

[BigA]

i just had to go and double check this, and i know mine is a 300 TDI but my cigarette lighter has a 20 amp fuse and is marked for a 20 amp fuse. Just saying as i thought the fact that i ad a 20 amp fuse may have been the reason i melted the wiring to a 3 way extension?

[POSBORNE]

On examing my fuse chart in the disco, it does state a 10A fuse for the cigeratte lighter. On returning to another moyorworld shop i was told/assured that changing the fuse to a larger 16A one would do harm, my only thought of the sales teamwas are any of you qualified auto electricians?

so i put my foot down and said that i wanted my money back, but had to settle with goods to the equal value of the returned fan heater.