1999 75 2.5 Connie - Battery drain.

YMGF · 28th April 2022, 08:55

(I posted this first by mistake in General forum. Can it be removed from there please)

I have a fairly high parasitic drain of around 140 mA. With my thanks to previous posters in various posts on this topic, I have isolated I believe four contributing circuits.

In pass fuse board:

F4 - 5A. Air conditioning and power windows. (According to owners handbook). contributes 12mA.

F21 - 30A. Power seats. Contributes 20mA

F23 - 20A. Sunroof. Contributes 24mA

Wiper motor, when connected at motor, contributes 43mA.

I've seen a post referencing the wiper motor but does anyone know the cause of the current consumption from this? I've checked the earth and continuity across the park switch and all seems ok. Also cleaned the area between the contacts. I'm reluctant for obvious reasons to replace it without better understanding first.

Reference the other circuits, does anyone have access to early circuit diagrams? The earliest I have on RAVE are 2003. Alternatively, any first hand knowledge of causes of current consumption in these circuits?

Without the above in circuit the current consumption is 37mA. I should say also that LSM is not connected and there is no factory sat nav or aftermarket additions.

Any assistance most appreciated.

Michael.

SD1too · 28th April 2022, 10:08

Hi Michael,

First of all can you not delete your post in the General section using the Edit button?

Regarding the drawn current, can you confirm that you have monitored this for at least 20 minutes with the car locked?

I also found that removing the wiper motor connector reduced the regular excursions I'm getting from 100 mA to 60 mA. There is a feed from the parking switch to the BCU (and rain sensor if fitted) which lets it know when to cut the power supply to the wipers. This only applies an earth connection. It's still a mystery to me why I get these high current excursions but it may be a faulty BCU (I had exactly this on my other car).

I think that you should reconnect the LSM so that the car is fully equipped to shut down as designed.

I have the 1999 wiring diagrams.

Simon

YMGF · 28th April 2022, 14:42

Thanks Simon. Yes I waited 20 mins or more before each measurement. I don't have rain sensor, but I'm also baffled by the wipers. The BCU is looking for a ground and I've checked that is what it's getting.
I'll connect the LSM though tomorrow and see if that changes anything.
Michael

28th April 2022, 08:55	#1
YMGF Regular poster Rover 75 Saloon Join Date: Jul 2020 Location: Oxford Posts: 68 Thanks: 33 Thanked 12 Times in 8 Posts	1999 75 2.5 Connie - Battery drain. (I posted this first by mistake in General forum. Can it be removed from there please) I have a fairly high parasitic drain of around 140 mA. With my thanks to previous posters in various posts on this topic, I have isolated I believe four contributing circuits. In pass fuse board: F4 - 5A. Air conditioning and power windows. (According to owners handbook). contributes 12mA. F21 - 30A. Power seats. Contributes 20mA F23 - 20A. Sunroof. Contributes 24mA Wiper motor, when connected at motor, contributes 43mA. I've seen a post referencing the wiper motor but does anyone know the cause of the current consumption from this? I've checked the earth and continuity across the park switch and all seems ok. Also cleaned the area between the contacts. I'm reluctant for obvious reasons to replace it without better understanding first. Reference the other circuits, does anyone have access to early circuit diagrams? The earliest I have on RAVE are 2003. Alternatively, any first hand knowledge of causes of current consumption in these circuits? Without the above in circuit the current consumption is 37mA. I should say also that LSM is not connected and there is no factory sat nav or aftermarket additions. Any assistance most appreciated. Michael.

28th April 2022, 10:08	#2
SD1too Doesn't do things by halves Rover 75 2.5 Connoisseur Auto (1999) Dealer launch model. Join Date: Mar 2007 Location: Former Middlesex Posts: 20,505 Thanks: 1,587 Thanked 3,749 Times in 3,181 Posts	Hi Michael, First of all can you not delete your post in the General section using the Edit button? Regarding the drawn current, can you confirm that you have monitored this for at least 20 minutes with the car locked? I also found that removing the wiper motor connector reduced the regular excursions I'm getting from 100 mA to 60 mA. There is a feed from the parking switch to the BCU (and rain sensor if fitted) which lets it know when to cut the power supply to the wipers. This only applies an earth connection. It's still a mystery to me why I get these high current excursions but it may be a faulty BCU (I had exactly this on my other car). I think that you should reconnect the LSM so that the car is fully equipped to shut down as designed. I have the 1999 wiring diagrams. Simon __________________ "Whatever is rightly done, however humble, is noble." Sir Henry Royce.

28th April 2022, 14:42	#3
YMGF Regular poster Rover 75 Saloon Join Date: Jul 2020 Location: Oxford Posts: 68 Thanks: 33 Thanked 12 Times in 8 Posts	Thanks Simon. Yes I waited 20 mins or more before each measurement. I don't have rain sensor, but I'm also baffled by the wipers. The BCU is looking for a ground and I've checked that is what it's getting. I'll connect the LSM though tomorrow and see if that changes anything. Michael