Engine bay 40A fuse keeps blowing

1. JTheLegandary Infrequent Poster Joined: Apr 2010 Kent Posts: 236 106 GTi 16v

   #1 14th September 2011, 16:18

   In the engine bay the 40A fuse at the back of the box keeps blowing ive tired so many things and its starting to drive me potty. Me and my dad have looked through the circuit diagrams in the haynes manual and im pretty sure the only thing that fuse is wired to is the interior fusebox. So im assuming that i can rule out anything inside the car being faulty because itd fuse out before it even got to the 40A fuse
   
   The only thing that i thought could be effecting it was that i have piggybacked off of the red wire behind the interior fusebox to power my amp + sub. I found it unclasped a few days ago so i taped it up replaced the fuse and it didnt blow for about a week. Then yesterday i came off my drive and scraped the bottom of my car and it cut out AGAIN. All other times ive replaced the fuse its blown within 2 minutes. Im beyond confused now and could really do with some advice here, it knocks out my windows, headunit, dash buttons, central locking.
   
   PLEASE HELP.
2. deks36 Saxperience Forum Bum Joined: Aug 2008 Herne Bay. Kent Posts: 3881 Peugeot 307, Nissan Juke, 206 Grand tourisme

   #2 14th September 2011, 16:48

   May I suggest you disconnect the amp for a while and see if that stops the fuse blowing if so then you have found you problem
3. JTheLegandary Infrequent Poster Joined: Apr 2010 Kent Posts: 236 106 GTi 16v

   #3 14th September 2011, 17:39

   I can see what you mean but surely if it was the amp then itd blow the fuse on the mains cable before it got to the 40A?
4. user_20080 Saxperience Hardcore! Joined: Dec 2007 smurfland. Posts: 17346 Ex saxo owner.

   #4 14th September 2011, 18:50

   You say you scrapped the bottom of your car are you sure you haven`t knocked an earth wire off in doing so?This being why your always blowing the fuse.
5. johnnyg_vts Established Member Joined: Dec 2006 Fleetwood Posts: 2244 2002 Saxo VTS

   #5 14th September 2011, 23:07

   Put a 50 amp fuse in. 
6. JTheLegandary Infrequent Poster Joined: Apr 2010 Kent Posts: 236 106 GTi 16v

   #6 15th September 2011, 09:47

   Quote:

   Originally Posted by stevo67 You say you scrapped the bottom of your car are you sure you haven`t knocked an earth wire off in doing so?This being why your always blowing the fuse.

   Possibly but do you know of any earthing points that are linked to the underside of the car? Or if you know the earthing point for the 40A cable (i have a feeling it might go straight back to the negative of the battery)
   
   

   Quote:

   Originally Posted by johnnyg_vts Put a 50 amp fuse in. 

   Well that sounds like a very bad idea..
7. JTheLegandary Infrequent Poster Joined: Apr 2010 Kent Posts: 236 106 GTi 16v

   #7 15th September 2011, 09:49

   Also i took the fuse out of my mains cable running to the amp, so theyre was no power going to it and tried ANOTHER fuse and it still blew. So that cancels out the possibility of it being the amp etc.
8. user_20080 Saxperience Hardcore! Joined: Dec 2007 smurfland. Posts: 17346 Ex saxo owner.

   #8 15th September 2011, 13:45

   Quote:

   Originally Posted by johnnyg_vts Put a 50 amp fuse in. 

   Are you wanting a car fire?
9. JTheLegandary Infrequent Poster Joined: Apr 2010 Kent Posts: 236 106 GTi 16v

   #9 17th September 2011, 10:54

   Anyone got any ideas, this is doing my nut!?
10. mikegriff L-plater Joined: Apr 2014 wigan Posts: 70 Renault clio 1.2 Saxo vtr mk2

    #10 9th July 2014, 21:52

    Anyone solved this problem, my saxo started this problem today on the way home from work. Cheers guys