td4 55reg battery drain

hi all, having trouble with battery draining over 2-3 days, took the vehicle to the local auto elecs he did the usual checks fuses relays and still showing drain, he thinks the ecu is not shutting down causing the drain. also its a coincidence that intermittently when cancelling the alarm central locking with the fob then opening the door the alarm light on the dash is flashing and beeping sound and radio switches its self on when previously it was off, also noticed when I turn the heater fan on engine revs increase 750 to 900 revs , battery in fob has been changed. ive read threads on battery drain, just hoping for suggestions

Is it wet inside?

Engine revs will increase with the fan on max. The ECU monitors the battery Voltage increasing the revs when a large drain is detected.

Have you always parked in the same location. The radio receiver can pick up other signals on the same frequency. External radio thermometers for instance use the same frequency. This can boot up the alarm ECU in readiness to receive the code. After a few seconds the ECU shuts down again.
I thought the ECU had a programme to prevent this after a few cycles but I could be wrong.

Nodge68 said:

Engine revs will increase with the fan on max. The ECU monitors the battery Voltage increasing the revs when a large drain is detected.

Have you always parked in the same location. The radio receiver can pick up other signals on the same frequency. External radio thermometers for instance use the same frequency. This can boot up the alarm ECU in readiness to receive the code. After a few seconds the ECU shuts down again.
I thought the ECU had a programme to prevent this after a few cycles but I could be wrong.

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That's a common problem on lots of vehicles from Honda Blackbirds to RR P38's.
OP, are you sure it's not just the battery suffering from the cold? A cold spell always shows up a weak battery.

what is your drain current ??

there was recently a thread about this

My Td4 drains 20 mA with everything off but the bonnet open

hi datatek, thanks for quick reply, been outside and checked inside footwells both sides dry no signs of damp, battery is 6mths old and was checked by the auto elec. thanks again.

spaniel man said:

hi datatek, thanks for quick reply, been outside and checked inside footwells both sides dry no signs of damp, battery is 6mths old and was checked by the auto elec. thanks again.

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Alternators can also be a source of battery drain if the diode pack is failing. You need to check the ECU's are going to sleep by monitoring battery current. Buy a cheap current clamp meter (WWW.CPC.co.uk)

hi nodge68, iv had the vehicle for 2yrs I always park on my drive same location ,the alarm symptoms is happening on my drive, at work and round town were I park up. the heater fan is set to1 when engine revs increase from 750 to 900,thanks.

Mine was draining as the REAR courtesy light was on, but of course, as it's in the raised part of the roof, I couldn't see it. (it was summertime and hence, quire light out when I parked it up).

Don't know how it got switched on !!!

digby said:

what is your drain current ??

there was recently a thread about this

My Td4 drains 20 mA with everything off but the bonnet open

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hi digby, auto elec said it was draining 0.8 amp,

Hi,
I put a thread up about this the other day.

http://www.landyzone.co.uk/lz/f9/anyone-td4-multimeter-244578.html

I have no solution yet though.

spaniel man said:

when cancelling the alarm central locking with the fob then opening the door the alarm light on the dash is flashing and beeping sound

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Hi cusi-bro, can't help with the drain sorry, but our '99 L Series will beep profusely at us sometimes when unlocking and entering the car. Only about 1 in 20 or so opens and as I say, the battery has never gone flat.

On a Td4 with PTC heater then when the dial is set to the red section then the engine revs rise to supply extra current from the alternator.

So that's normal behaviour.

I suspect the issue is caused by the door issue which is meaning the car won't go to sleep properly and reduce the current drain

td4van said:

On a Td4 with PTC heater then when the dial is set to the red section then the engine revs rise to supply extra current from the alternator.

So that's normal behaviour.

I suspect the issue is caused by the door issue which is meaning the car won't go to sleep properly and reduce the current drain

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Hi td4van, checked the heater issue your right , one to cross off the list, booked into a independent next week he says this issue should show up on t4 diagnostic plenty off checks to do before he condemns the ecu, hope to keep site posted.

td4van said:

On a Td4 with PTC heater then when the dial is set to the red section then the engine revs rise to supply extra current from the alternator.

So that's normal behaviour.

I suspect the issue is caused by the door issue which is meaning the car won't go to sleep properly and reduce the current drain

Click to expand...

The PTC heater on mine only comes on when the switch is at the end of the red section and when you can feel a definite click.