My fuses keep melting

[Metalman]

I cant figure this one out so i thought i'd ask if anyone else has had the same problem? The two 15a fuses for the heater/air con keep melting and they've started melting the fuse box, but the fuses never blow. If i turn the heater on and touch the fuses they really are very hot, does this mean the blower motor is on it's way out? The 40a fuse under the dash melted last night whilst doing 50 mph on an un-lit road, so i had no lights and the engine cut out, very scary! (Lucky i had a spare 40a fuse to get me home though.) Any thoughts would be much appreciated! Thanks guys.

[Gnits]

Probably not going to help but I have just noticed this in my case it is two 30 amp fuses. Did have a root around cos the car was not starting and the neg terminal on the battery was loose - no idea if this is the cause of the fuse issue though but might be worth a check? My wiring is kind of Subaru cos I don't have a Noble : (

[bernhund]

My yellow fuse for the fuel pump kept melting on my 2.5. This is the fuse box behind the drivers head under the rear clam. The box is prone to poor connections and will melt the fuses even if it doesn't blow them. Try cleaning the terminals up a bit and possibly squeezing them up a bit tighter. My fuses have lasted longer since I did that but I will be fitting a more protected box in the spring. Probably not a Noble one but something enclosed.

[Adrian W]

I would be checking the carriers, the heat may be from the contacts arcing

[joust]

As Adrian says the heat will be coming from the contact to fuse connection arcing, not the fuse itself. Normal cause is corrosion that increases the resistance to a significant enough level to make it into a little mini heater element.

A good dose of switch cleaner (proper stuff from Maplins is a million times better than WD-40 which will be OK but not ideal) and then push in and pull out the fuse 10-20 times, wiping the contact "blades" on the switch each time.

If you want to do it properly get some of this
http://www.maplin.co.uk/Module.aspx?ModuleNo=4153 (due in 7 days, this will be just as good http://www.maplin.co.uk/Module.aspx?ModuleNo=27515 - in stock)
it also prevents the arcing which is probably causing the problem.

To stop it happening again once you've cleaned it up, use this stuff http://www.maplin.co.uk/module.aspx?moduleno=34603...

[Metalman]

Great advice guys, thanks a lot, I'll get the car out tomorrow and give it all a good clean up and check all connections around the fuse box and the battery etc and buy some of that stuff from maplins to hopefully stop it happening again. It's cheared me up now i dont have to get the blower motor out!

[Metalman]

Well i've had a good look over the electrics and it seems the hoses to the heater matrix have been dripping onto the fuse box and it's corroded, and some of the melted plastic is quite bad. So, has anyone got a spare fusebox they would sell as i'd like to replace the lot?