Rover 75 CDTi Tourer (2004) - Interior lights fuse keeps blowing

cobra · 3rd November 2008, 12:20

Hi there,

I am a new member (based near Newbury, Berkshire) but have had a Rover 75 for just over a year. I recently changed my 75 Classic SE CDT saloon for a face lift Connoisseur CDTI tourer (2004).

Anyhow, I have a problem with the interior lights. The fuse keeps blowing but none of the bulbs are faulty. I even tried a 15 amp fuse instead of the 10 amp required. This also blew. I have checked for most of the earth connections and they seem fine.

I have been through the wiring diagram for the lights and find that they are controlled by the body control unit. I now suspect that this may be the cause of my problem, as I have also found that the heated rear screen only has one element working. All the others appear to have burned out at the edge of the screen. ie this is not damage caused by scratching the elements.

As both these circuits are controlled by the BCU it seems likely that this is the cause.

Can anyone either confirm this or offer any others suggestions as to the possible cause.

Also can anyone give me an idea of how much a replacement BCU would be and where I could get one. Also where is it?

Thanks Tom

Greeners · 3rd November 2008, 14:05

The BCU is located passenger side, above the fuse box.

Moonstone · 3rd November 2008, 15:08

BCU is around £120 but likely to need at least 1 hour's labour at an ex-dealer for programming. Take key bar-codes if you have them.

Dealer's computer may also be able to confirm fault diagnosis.

JohnDotCom · 3rd November 2008, 18:24

You need the correct part number off of old unit as there are several non interchangeable BCU units.

cobra · 4th November 2008, 08:03

Quote:

Originally Posted by Greeners

The BCU is located passenger side, above the fuse box.

Thanks for the info.
Is the accessibility the same as the fuse box, ie can I get to it the same way or do I need to take anything else off?

Quote:

Originally Posted by Moonstone

BCU is around £120 but likely to need at least 1 hour's labour at an ex-dealer for programming. Take key bar-codes if you have them.

Dealer's computer may also be able to confirm fault diagnosis.

I don't have the key bar-codes (is this likely to be a problem?). Also why does the unit need to be programmed? Is it to do with what options you have on the car?

I now have another problem - the air bag warning light has also come on. Is this linked to the BCU?

Does anyone have any other suggestions as to my faults:
Interior light fuse blowing
Heated rear screen burning out (it appears)
air bag warning light on

Any help is much appreciated.

JohnDotCom · 4th November 2008, 08:14

Air Bag warning light is generally the connections under seats.
Plenty written up on these before.
They come apart due to movement of seat.

pondweed · 4th November 2008, 08:19

how long ago did you get it and can you take back to the dealer....? Sounds like a problem that might have been there or indeed a reason someone else knew about?

Are there any other pieces of electrical kit in areas where water can get to?(spare wheel well etc)

cobra · 4th November 2008, 11:08

Quote:

Originally Posted by pondweed

how long ago did you get it and can you take back to the dealer....? Sounds like a problem that might have been there or indeed a reason someone else knew about?

Are there any other pieces of electrical kit in areas where water can get to?(spare wheel well etc)

Had the car for a month and no I can't take it back. The problem was there, I guess, but wasn't obvious to begin with. I did replace the fuse and the lights worked for a while before blowing again. Also I only recently needed to use the heated rear screen. I have repaired the heated screen using electrical paint and some wire. However I still don't know what caused the problem in the first place.

Don't know of any electrical equipment in wet areas.

cobra · 4th November 2008, 12:34

Quote:

Originally Posted by JohnDotCom

Air Bag warning light is generally the connections under seats.
Plenty written up on these before.
They come apart due to movement of seat.

Thanks JDC, I moved the wires under the seat about and the light has now gone off. One less thing to worry about

Moonstone · 4th November 2008, 17:21

Interior lights are driven from BCU. HRW relay is switched by BCU (for air temperature control).

The bar-codes are used to program the key fob transmitters for central locking. Ex-dealer may be able to read old unit. There are also user options which can be programmed for windows, locking, etc, though again, the computer might be able to read existing settings.

3rd November 2008, 12:20	#1
cobra Newbie Rover 75 Connoisseur CDTI FaceLift Tourer (2004) Join Date: Sep 2008 Location: Newbury Posts: 8 Thanks: 0 Thanked 0 Times in 0 Posts	Rover 75 CDTi Tourer (2004) - Interior lights fuse keeps blowing Hi there, I am a new member (based near Newbury, Berkshire) but have had a Rover 75 for just over a year. I recently changed my 75 Classic SE CDT saloon for a face lift Connoisseur CDTI tourer (2004). Anyhow, I have a problem with the interior lights. The fuse keeps blowing but none of the bulbs are faulty. I even tried a 15 amp fuse instead of the 10 amp required. This also blew. I have checked for most of the earth connections and they seem fine. I have been through the wiring diagram for the lights and find that they are controlled by the body control unit. I now suspect that this may be the cause of my problem, as I have also found that the heated rear screen only has one element working. All the others appear to have burned out at the edge of the screen. ie this is not damage caused by scratching the elements. As both these circuits are controlled by the BCU it seems likely that this is the cause. Can anyone either confirm this or offer any others suggestions as to the possible cause. Also can anyone give me an idea of how much a replacement BCU would be and where I could get one. Also where is it? Thanks Tom Last edited by cobra; 3rd November 2008 at 12:53..

3rd November 2008, 14:05	#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	The BCU is located passenger side, above the fuse box. __________________ *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]

3rd November 2008, 15:08	#3
Moonstone Loves to post Rover 75 Tourer Join Date: Nov 2006 Location: Scotland Posts: 412 Thanks: 0 Thanked 1 Time in 1 Post	BCU is around £120 but likely to need at least 1 hour's labour at an ex-dealer for programming. Take key bar-codes if you have them. Dealer's computer may also be able to confirm fault diagnosis.

3rd November 2008, 18:24	#4
JohnDotCom * Rover 75 FaceLift Tourer CDTi 170BHP Auto ConnSE 2005 Model Starlight Silver Join Date: Nov 2006 Location: Abergele Posts: 28,735 Thanks: 0 Thanked 6 Times in 5 Posts	You need the correct part number off of old unit as there are several non interchangeable BCU units.

4th November 2008, 08:14	#6
JohnDotCom * Rover 75 FaceLift Tourer CDTi 170BHP Auto ConnSE 2005 Model Starlight Silver Join Date: Nov 2006 Location: Abergele Posts: 28,735 Thanks: 0 Thanked 6 Times in 5 Posts	Air Bag warning light is generally the connections under seats. Plenty written up on these before. They come apart due to movement of seat.

4th November 2008, 08:19	#7
pondweed This is my second home Waiter, Waiter! I seem to have a Roomster in my drive... Join Date: Nov 2006 Location: Sussex Posts: 3,268 Thanks: 0 Thanked 1 Time in 1 Post	how long ago did you get it and can you take back to the dealer....? Sounds like a problem that might have been there or indeed a reason someone else knew about? Are there any other pieces of electrical kit in areas where water can get to?(spare wheel well etc)

4th November 2008, 17:21	#10
Moonstone Loves to post Rover 75 Tourer Join Date: Nov 2006 Location: Scotland Posts: 412 Thanks: 0 Thanked 1 Time in 1 Post	Interior lights are driven from BCU. HRW relay is switched by BCU (for air temperature control). The bar-codes are used to program the key fob transmitters for central locking. Ex-dealer may be able to read old unit. There are also user options which can be programmed for windows, locking, etc, though again, the computer might be able to read existing settings.