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overnight battery drain


Accelerating Away
After a couple of months without needing money spending on it the new year has suddenly brought a new problem. The car has run great since the second engine rebuild until saturday morning, when i tried to start it and the battery was completely flat. A jump start got it going and i went to get the battery checked, although this is only 6 months old and it was fine and so was the alternator. Today (sunday morning) it started with no problems, but this afternoon it struggled. So i sat inside and locked the doors, after 2 minutes the little red light on the gear stick went out as the car went to sleep, 5 minutes later it came back on, but this has only happened once. Would this flatten the battery in a few hours?? alternatively can anyone suggest anything else to try.
Hope someone can help.
Oh it`s a 4.6 hse 1996 on lpg/petrol.
If something is waking up the BECM it will drain the battery fairly quickly. In sleep mode with the alarm activated, the BECM draws 40 mA. Once it is woken up, it draws 1 Amp.

I *think* it might need to be diagnosed on Testbook, but Jon V8 will know for sure.
Thanks for all the ideas, Yesterday i did make up some long leads and put my ammeter across the negative side of the battery. After the 2 minutes to shut down the car rested for between 2 and 12 minutes, it then woke up for 2 minutes then the whole thing started again. So i removed the rf receiver and tested the car again, 1.1/2 hours and no waking up, so i have left it off for now. This morning the car turned over like it had got a new battery on it. So i will leave it for a few more days with the rf receiver off and if it`s still ok i will go and get the new upgraded one Thanks again for all of your help, and i will let you know how it goes.
The car has sat for 2 days now and no battery drain so i am going to order a new rf receiver part no ywy500170. Does anyone know how i can tell if they have supplied the correct part number, as the dealers are telling me that if it doesn`t cure it they wont exchange the part untill they have had the car in for tests and confirmed that the rf reciever is at fault. Could they give me the old part in a new box in order to get a few hours easy labour out of me. I am certain this part is the cause of the battery drain but unsure that they will supply the correct part as i am fitting it myself. If anyone has a comparison of the old and new and what to look for on casing or box it would be greatly appreciated.
I keep seeing people referring to the little light on the gearlever which from what I can make out indicates whether the BEcm is awake or asleep. Is this a model specific thing as I've looked on mine and there definately doesn't seem to be any lights there at all (other than the gear indicator ones obviously). Mine is a 95 4.6HSE
On the automatic selector when the ignition is on there is a little red light that shows what gear is selected. When the ignition is off and the keys removed the light glows dimly,(this you can see better when it`s dark) after 2 minutes this should go out completely as the becam goes to sleep.
Hope this helps
I checked mine in the dark tonight and, as soon as I pull the ignition key, the light goes out. Definately doesn't glow even remotely dimly.
Turned out it was a duff battery. Lucky it was only 12 months old and still under guarantee so I am back to normal again.
Hi all been a p38 owner for 10 years had this problem for last few years just found out that's it's the RF receiver now got a new one but when I received it its same as old one same numbers stamped on it in plastic.PA6GF30
The only difference is white sticky label which says MPT 1340 which is the new one I just put on and old one says MPT 10739
there is no ref to part numbers on this item. so could av been sold old stock for all i know

Can anyone help with this please what is MPT ???????
many thanks BOB
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