How quickly can a dodgy alarm receiver drain the battery?

This site contains affiliate links for which LandyZone may be compensated if you make a purchase.
J

jerrytlr

New Member
Posts
307
Location
Dordogne, France
Went to start the P38 yesterday and the battery was flat - and I mean TOTALLY flat, not even a glimmer from the dash lights, nothing. As though it was disconnected.

I hadn't used the car for about 3 days.

Could the dodgy RF receiver issue (keeping the BECM awake) cause this, or would it take longer than that to completely discharge the battery? Should I be looking for something else? Any easy tests I should be doing, other than disconnecting the RF wire (which I will do)?

Battery is large capacity and about 2 months old. Charged it for a few hours and everything OK afterwards, car started fine.

Just looking for suggestions really....... I know there have been plenty of other threads on battery drain but going from OK to totally dead in 3 days seems a bit extreme.....


Cheers,

Jerry
 
Hi i had same issue with mine battery drain on new battery although i had other issues it was all basically down to the r/f unit:) due to help on here, i am now running at present with the old r/f but with blue wire disconnected and at present everything is fine. so i would try that first i think.
 
Thanks guys, it seems the RF problem can flatten the battery that quickly (and completely!) then.

A few tests just done:

current drain 2ish Amps for a few seconds after unlocking, then around 0.6A for a few minutes then down to 0.03A (30mA), presumably this is when the BECM has gone to sleep? I think 30mA is reasonable for radio presets etc, so hopefully there is no current draw from anything else once the BECM is asleep, which would I guess point to the RF unit waking it up all the time. Do these numbers seem sensible?

I have just disconnected the blue wire and will see how it goes. BTW I am surprised how well the remote still works with it disconnected - I can certainly live with it like this if necessary (new RF unit a long way down the list of expenses my car is expecting from me....)


Thanks again

Cheers

Jerry
 
Hi, I also had this problem of draining and due to the help of these guys I disconnected the receiver. Problem solved. I leave it for 3 to 4 days at a time and it fires up no problem at all.
The only down side is that I have to stand close to the vehicle to lock or unlock.

Good luck
 
Hope it works for you it did for me as stated on other thread i replaced r/f with new upgraded one and in short after fitting two that appeared faulty,
courtesy of island 4x4 i'm now running with the old one with blue wire disconnected and yes surpised me at how well the remote works, the reason i am still going to replace r/f with new one at some stage, is after having both front door mechs replaced i understand that these can be burnt out by the old r/f. but not sure if this can happen if blue wire disconected perhaps someone can advise.
 
jerrytlr said:
Thanks guys, it seems the RF problem can flatten the battery that quickly (and completely!) then.

A few tests just done:

current drain 2ish Amps for a few seconds after unlocking, then around 0.6A for a few minutes then down to 0.03A (30mA), presumably this is when the BECM has gone to sleep? I think 30mA is reasonable for radio presets etc, so hopefully there is no current draw from anything else once the BECM is asleep, which would I guess point to the RF unit waking it up all the time. Do these numbers seem sensible?

I have just disconnected the blue wire and will see how it goes. BTW I am surprised how well the remote still works with it disconnected - I can certainly live with it like this if necessary (new RF unit a long way down the list of expenses my car is expecting from me....)


Thanks again

Cheers

Jerry
Click to expand...

A 2 amp draw will flatten the battery pretty quickly, 30ma when the BECM is asleep is correct. A duff RF unit can go into a failure mode where it burns the door locks out by continually sending the lock command, this can happen even with the blue aerial wire disconnected:eek:
 
Thanks for the advice datatek hope jerrytir reads this, i actually spoke to dougdotcom earlier today and he said the same,so i'm off to order a new r/f unit from maindealer. in the hope i get good one.Once again great advice from on here many thanks.:)
 
Yup I've ready it :) And Keith, thanks for confirming that 30mA is OK.

If the RF unit is constantly sending lock, is there any way of detecting this, other than waiting for the locks to fail?? Does it cause the locks to make a noise?

I'll be getting a new RF unit soon but would be happier knowing that it wasn't torturing my door locks in the meantime...

Need to check the Nanocom documentation, perhaps that can 'see' the 'lock' command from the RF unit?

Kaiser - have you had trouble sourcing the new RF unit from Island? I've found them pretty good for stuff so far...

Cheers

Jerry
 
Just looked at the Nanocom documentation, in the BECM module, it has this:

---
RF Memory
(Automatically reads the RF Memory)
Clear RF memory
This resets the memory, which stays reset until a valid fob code has been received by the BECM. These then
stay set until reset with this function.
---

So if I reset the memory, and no valid fob code is received, surely the RF receiver must be OK? Similarly, if it sending 'lock' all the time, this memory should fill up quite quickly even though no actual key fob press has been made?

Am I understanding this properly??


Cheers

Jerry
 
Not exactly. When the RF receiver starts to fail, it does things randomly so you may see nothing at the time you are looking and five minutes later it will try to cook your locks.
 
I had the same problem with the early RF unit. After receiving good advice here, I replaced it with the latest unit from a LR dealer de-stocking on ebay. Works perfectly and an easy and relatively cheap fix.
 
Datatek said:
Not exactly. When the RF receiver starts to fail, it does things randomly so you may see nothing at the time you are looking and five minutes later it will try to cook your locks.
Click to expand...

Ah I see, so could be fine for ages and not log any lock request, and then cook the locks by going beserk for a few minutes. That is a much harder issue to deal with!

Those leaking oil pipes and PAS pipes may have to wait then - the price for OEM replacement from Island is around £150+VAT, but it seems Kaiser has had issues with the reliability of those, anybody know what the price is from a L/R dealer?

Cheers,

Jerry
 
jerrytlr said:
Ah I see, so could be fine for ages and not log any lock request, and then cook the locks by going beserk for a few minutes. That is a much harder issue to deal with!

Those leaking oil pipes and PAS pipes may have to wait then - the price for OEM replacement from Island is around £150+VAT, but it seems Kaiser has had issues with the reliability of those, anybody know what the price is from a L/R dealer?

Cheers,

Jerry
Click to expand...

About the same, you could try a few dealers over here.
 
jerrytlr said:
Ah I see, so could be fine for ages and not log any lock request, and then cook the locks by going beserk for a few minutes. That is a much harder issue to deal with!

Those leaking oil pipes and PAS pipes may have to wait then - the price for OEM replacement from Island is around £150+VAT, but it seems Kaiser has had issues with the reliability of those, anybody know what the price is from a L/R dealer?

Cheers,

Jerry
Click to expand...


hi, jerry may i suggest that you ring emmotts of colne on 01282859468 speak to either joe or jess and ask for a series 3 rf reciever this works as i have one fitted recently and only today ive been out to tescos in wigan which their masts etc had locked out two chaps pete and marty from their rangie , on arrival my car was fine with the masts etc so resynced theirs and made two nice lads very very happy and after buying me breakfast off they went over the moon :D:D:D,, emmotts will ship to europe no probs and brilliant people to deal with and they are our sponsers on landyrange

hope this all helps ,kind regards MOZZ:):):):):):):)
 
mozz smith said:
hi, jerry may i suggest that you ring emmotts of colne on 01282859468 speak to either joe or jess and ask for a series 3 rf reciever this works as i have one fitted recently and only today ive been out to tescos in wigan which their masts etc had locked out two chaps pete and marty from their rangie , on arrival my car was fine with the masts etc so resynced theirs and made two nice lads very very happy and after buying me breakfast off they went over the moon :D:D:D,, emmotts will ship to europe no probs and brilliant people to deal with and they are our sponsers on landyrange

hope this all helps ,kind regards MOZZ:):):):):):):)
Click to expand...

Nice one MOZZ:D
 
You must log in or register to reply here.

Similar threads

Blob
L322 (Not your usual) battery drain
Replies
7
Views
2K
Datatek
Datatek
K
Fuse 49 aka Battery drain on L322
Replies
5
Views
1K
Rallymantony
R
K
2005 L322 Transfer Failsafe (3 year problem, still unsolved).
Replies
8
Views
558
Bemble
B
Andy Burrell
P38A Do I reconnect the RF receiver?
Replies
12
Views
1K
Rubberknees
Rubberknees
kermit_rr
L322 keyfob signal not received
3 4 5
Replies
93
Views
4K
kermit_rr
kermit_rr
Back
Top