Fuse 3 blows instantly

Bolin · 30th March 2011, 20:19

Hi all

I have an odd wiring problem. Fuse no. 3 blows instantly when it is put into the fusebox, with a little bit of a 'flash'. This fuse is for the clock and driver's memory seat according to my handbook (Haynes says it also does the diagnostic socket).

It's been like this since I bought the car, the seller said that he ans his wife kept moving the seats lots, ans then it broke, and that there was a problem with the fuse. It appears that he had a go at it, as I found an empty fuse packet near the clock, behind the dashboard!

The fuse blows even with the 8-pin driver's seat connector and the clock both unplugged.

I'm thinking that it could be chaffed wiring under the carpet near the driver's seat, a result of it being moved so much? Problem is, I can't check the wiring to look for chaffing as I need to remove the carpet (needs removing anyway due to wet floor), to remove the carpet I need to remove the driver's seat, to remove the driver's seat I need to move the seat back to access the rear bolts, to move the seat back I need to fix it, to fix it I need to check the wiring etc................

Can anybody help or have any ideas?

Thanks, Bolin.

Greeners · 30th March 2011, 20:21

Have you checked the diagnostic socket for damage ?

T-Cut · 30th March 2011, 20:25

What year is the car? (put it in your profile). The fuses vary between pre and post facelift. They may also vary through evolution before the facelift phase. Fuse 3 (interior box) is for the cigar lighter only in mine.

TC

Bolin · 30th March 2011, 20:32

Thanks for the replies guys - I haven't checked the socket for damage, will do that.

Car is 2001, so has the earlier fusebox.

HarryM1BYT · 30th March 2011, 21:20

Rather than repeatedly replacing the fuse, wire a 6w lamp across a blown fuse and waggle the wiring about in the relevant areas - when the lamp goes out or flickers, you have found the short.

T-Cut · 30th March 2011, 21:39

Ignore my ramblings.

TC

HarryM1BYT · 30th March 2011, 21:45

No!

The worst case would be that with a dead short the lamp can only have 12v across it - which would make the lamp light at full brightness.

Mike Noc · 30th March 2011, 21:46

Nope - bulbs are meant to be fitted between positive and ground. That's what makes them glow!

Mike

T-Cut · 30th March 2011, 22:23

That's what I was trying to say!

TC

raykay · 30th March 2011, 23:34

Quote:

Originally Posted by mikeseignot

Nope - bulbs are meant to be fitted between positive and ground. That's what makes them glow!

Mike

If the fuse is blowing because of a short, it means that somewhere along the live side if the circuit after the fuse, something is touching earth.

As HarryM1BYT has said, if you replace the fuse with a lamp, it will light as it has 12v from the live side of the fuse holder and earth from the the fault in the circuit on the other side of the fuse holder.

The lamp will go out when it loses the connection to earth when the fault has been found and rectified.

30th March 2011, 20:19	#1
Bolin This is my second home Rover 75 2.5 V6 Connoisseur SE 4dr manual Wedgewood Blue 2 04-05/06/2001 Join Date: Nov 2006 Location: N.E. Hampshire Posts: 4,620 Thanks: 289 Thanked 308 Times in 243 Posts	Fuse 3 blows instantly Hi all I have an odd wiring problem. Fuse no. 3 blows instantly when it is put into the fusebox, with a little bit of a 'flash'. This fuse is for the clock and driver's memory seat according to my handbook (Haynes says it also does the diagnostic socket). It's been like this since I bought the car, the seller said that he ans his wife kept moving the seats lots, ans then it broke, and that there was a problem with the fuse. It appears that he had a go at it, as I found an empty fuse packet near the clock, behind the dashboard! The fuse blows even with the 8-pin driver's seat connector and the clock both unplugged. I'm thinking that it could be chaffed wiring under the carpet near the driver's seat, a result of it being moved so much? Problem is, I can't check the wiring to look for chaffing as I need to remove the carpet (needs removing anyway due to wet floor), to remove the carpet I need to remove the driver's seat, to remove the driver's seat I need to move the seat back to access the rear bolts, to move the seat back I need to fix it, to fix it I need to check the wiring etc................ Can anybody help or have any ideas? Thanks, Bolin.

30th March 2011, 20:21	#2
Greeners Moderator MG-ZTT Join Date: Mar 2007 Location: Ware, Herts Posts: 19,798 Thanks: 161 Thanked 1,249 Times in 1,036 Posts	Have you checked the diagnostic socket for damage ? __________________ *David* Impecunity is the mother of ingenuity Useful how to's for common problems Car Of The Month Jan 2014 [SatNav Power Down] [Coolant Level] [SatNav Repair] [Diesel Non Starting] [Paint Codes] [Rear Light Seals] [Reversing Light Switch] [Bleeding Brakes][Sunroof Drain] [Early ZT's][Instrument Pack Diagnostics][ATC Diagnostics]

30th March 2011, 21:20	#5
HarryM1BYT This is my second home 75 Contemporary SE Mk II 2004 Man. Sal. CDTi 135ps, FBH on red diesel, WinCE6 DD Join Date: May 2010 Location: Leeds Posts: 17,273 Thanks: 2,160 Thanked 2,061 Times in 1,586 Posts	Rather than repeatedly replacing the fuse, wire a 6w lamp across a blown fuse and waggle the wiring about in the relevant areas - when the lamp goes out or flickers, you have found the short. __________________ Harry How To's and items I offer for free, or just to cover the cost of my expenses... http://www.the75andztclub.co.uk/foru...40#post1764540 Fix a poor handbrake; DIY ABS diagnostic unit; Loan of the spanner needed to change the CDT belts; free OBD diagnostics +MAF; Correct Bosch MAF cheap; DVB-T install in an ex-hi-line system; DD install with a HK amp; FBH servicing. I've taken a vow of poverty. To annoy me, send money.

30th March 2011, 21:39	#6
T-Cut This is my second home Rover75 and Mreg Corsa. Join Date: Nov 2006 Location: Sumweer onat mote o'dust (Sagin) Posts: 21,753 Thanks: 341 Thanked 3,660 Times in 2,924 Posts	Ignore my ramblings. TC Last edited by T-Cut; 30th March 2011 at 21:43..

30th March 2011, 21:45	#7
HarryM1BYT This is my second home 75 Contemporary SE Mk II 2004 Man. Sal. CDTi 135ps, FBH on red diesel, WinCE6 DD Join Date: May 2010 Location: Leeds Posts: 17,273 Thanks: 2,160 Thanked 2,061 Times in 1,586 Posts	No! The worst case would be that with a dead short the lamp can only have 12v across it - which would make the lamp light at full brightness. __________________ Harry How To's and items I offer for free, or just to cover the cost of my expenses... http://www.the75andztclub.co.uk/foru...40#post1764540 Fix a poor handbrake; DIY ABS diagnostic unit; Loan of the spanner needed to change the CDT belts; free OBD diagnostics +MAF; Correct Bosch MAF cheap; DVB-T install in an ex-hi-line system; DD install with a HK amp; FBH servicing. I've taken a vow of poverty. To annoy me, send money.

30th March 2011, 20:25	#3
T-Cut This is my second home Rover75 and Mreg Corsa. Join Date: Nov 2006 Location: Sumweer onat mote o'dust (Sagin) Posts: 21,753 Thanks: 341 Thanked 3,660 Times in 2,924 Posts	What year is the car? (put it in your profile). The fuses vary between pre and post facelift. They may also vary through evolution before the facelift phase. Fuse 3 (interior box) is for the cigar lighter only in mine. TC

30th March 2011, 20:32	#4
Bolin This is my second home Rover 75 2.5 V6 Connoisseur SE 4dr manual Wedgewood Blue 2 04-05/06/2001 Join Date: Nov 2006 Location: N.E. Hampshire Posts: 4,620 Thanks: 289 Thanked 308 Times in 243 Posts	Thanks for the replies guys - I haven't checked the socket for damage, will do that. Car is 2001, so has the earlier fusebox.

30th March 2011, 21:46	#8
Mike Noc This is my second home Rover 75 CDT Manual Connoisseur SE, Rover 75 CDT Automatic Connoisseur SE & a Freelander Td4. Join Date: Jul 2009 Location: Hampshire Posts: 11,570 Thanks: 3,470 Thanked 3,119 Times in 2,247 Posts	Nope - bulbs are meant to be fitted between positive and ground. That's what makes them glow! Mike

30th March 2011, 22:23	#9
T-Cut This is my second home Rover75 and Mreg Corsa. Join Date: Nov 2006 Location: Sumweer onat mote o'dust (Sagin) Posts: 21,753 Thanks: 341 Thanked 3,660 Times in 2,924 Posts	That's what I was trying to say! TC