how to change battery, anything special required?

[Eevo]

hi all, i didnt realise leaving the doors unlocked causes drain on the battery.
its been two weeks and now i have a battery at 4 volts.


i have a new battery ready but im unsure if i can simply swap it or if i need codes handy or anything else



cheers

[Scouse]

hi all, i didnt realise leaving the doors unlocked causes drain on the battery.Doors unlocked doesn't affect the battery.


Leaving the key in the ignition will though, as well as electrical interference as the BECM will not go to sleep.






You'll need the radio code & then reset all the windows & sunroof by cycling them fully open then closed.
The key will need to be re-synchronized to the car too.

[Eevo]

Doors unlocked doesn't affect the battery.
oh i read that it would. moving on.






The key will need to be re-synchronized to the car too.

and how is this done?

[Keithy P38]

I think it depends on your year model!

My '99 P38 has had the battery out multiple times. When it comes time to put the battery back in, I ensure the drivers door is open, but otherwise have never needed to re-sync keys or input radio codes! All I've needed to do is reset the windows.

Cheers
Keithy

[daf11e]

Your right Kiethy I too have changed my battery a number of times (especially when I had rf problems) and never had an issue with anything except the standard windows and sunroof...........mine is a 2000

[finallyrangie]

my battery has also been in and out many times,

the manual said to leave the drivers door open and the key in the ignition (switched off) tells the computer you haven't stolen the car, apparently.


I always do it just because it's easy enough and I also only have to reset windows and sunroof

mine is a 1995

[p38arover]

I think leaving the car in anything other than Park will also flatten the battery. I think the BECM doesn't go to sleep.

[TheTree]

I think it also depends on how long you have the battery disconnected.

It seems that if you are over about 20 mins ( the SRS discharge time) then you may need to re-sync the key but you always have to do the windows and sunroof.

Oh and leaving an OBD device connected can keep waking the BECM and kill your battery as well.

Steve

[mtb_gary]

I've never had to re sync the key after having the battery disconnected. Apart from the straight forward windows and sunroof calibration I have found the most time consuming part to be reprogramming the radio stations after re entering the radio PIN. (1996 HSE)

Gary

[Eevo]

good news.

using my jump starter as listed in this thread
http://www.aulro.com/afvb/2336289-post13.html

was able t jump the 4.6

no syncing required. everything seems to work. windows go up n down as usual.

now to work out why the battery was down at 3 volts

[daf11e]

Eevo is this the first time your battery has gone flat with no use for a couple of weeks?

[Eevo]

Eevo is this the first time your battery has gone flat with no use for a couple of weeks?

yes, been sitting ~2 weeks
only owned car for about 3 months

[daf11e]

Whilst I'm sure you know of many things including a duff battery in the first place causing your problems just keep in mind the RF receiver which is behind the rear seat behind the driver.......I believe it doesn't happen to many P38s but it sure did mine and after many months and two new batteries later I disconnected the receiver and havnt had a problem for 2 years. This all happened when I moved house into a new location obviously interference in my new location..............but as I say mate probably not but keep in mind.

[Eevo]

cheers.
im not using the remote as the buttons have worn away.
so im key locking at the moment

[daf11e]

Understood but the receiver still connected at the rear is awake.......just keep in mind.

[Eevo]

Understood but the receiver still connected at the rear is awake.......just keep in mind.

yes yes, i understood.
i'll be having a look this weekend if i get time

[Scouse]

cheers.
im not using the remote as the buttons have worn away.
so im key locking at the momentDon't buy the 'refurb' kits off eBay as they're dearer than from a dealer. The button cover is only a couple of $ from LR & the battery cover is cheap too.

[Eevo]

Don't buy the 'refurb' kits off eBay as they're dearer than from a dealer. The button cover is only a couple of $ from LR & the battery cover is cheap too.

now you tell me, lol
i ordered the $8 one from ebay last night