P38A Flat battery, the problems have started...

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

Flossie

Well-Known Member
Posts
10,523
Location
Shropshire
Any pointers lads?:D
2001 dhse (with cupholders dunt cha know:cool:).
A recap just incase...
Owned around 3 weeks, stood for 4 yrs. Fitted new massive handkok battery less than 2 weeks ago. Fires up fine. Has not been started for at least a week then needed to move her yesterday, loads of umph in the battery and she fired up great.
I've just been out to start her again and the dash lights won't even glow, battery is at 2.4 bolts, flat as a witches tit:mad:
Apart from the Doris washing the outside and polishing the glass inside this morning, nothing has changed. Bear in mind she was left for a week with no ill effects and the dead battery has occurred between tea time yesterday and tea time today.
Battery is on charge now.
First thing to check??
 
This is why I said not to leave the new battery on til you’ve had a look at the electrics. Once it’s flattened completely they are never quite right.
First thing is charge the battery. This will take couple of days sticking it on for couple of hours won’t suffice if its flat flat.
Then you reconnect and test for parasitic draw (wait til becm is fully asleep)
 
But but...it was fine fer a week so I thought it was all ok:oops:.
Update- Doris sez she had the driver's door open all day but sez she turned off the centre interior light as soon as she got in. Would leaving the door open cause a drain? Or point to a fault elsewhere maybe?
Just ordered one of those things Brian linked to above, looks useful:cool:
 
She's also had the tail gate open all day too. She's trying to air it out(which is working) cos it smelt stale, not so much now.
No keys in the ignition at all btw.
 
Would leaving doors open, keys out, all interior lights out, keep the becm awake?
I ask cos the only thing different from holding a full charge for a whole week and going flat in 24hrs or less is that the front doors and tailgate were open.
 
Do you know how to do a parasitic draw test?
Can you see it in the night? If the BECM wakes up for some reason you will tell on an auto as the light on the prindle stick will glow if it wakes. Many stories of people sitting silently not moving inside p38s watching the prindle. Makes the neighbours talk but works.
 
Sadly, that NEW battery may be pretty much Donald-Ducked now. :(
If you want to leave it all "open" to air it, put it in a secure garage and disconnect the battery and use a mains blower/heater to push air through it to get rid of the fags/dead-dog/rotten-fish smells. ;)
 
Do you know how to do a parasitic draw test?
Can you see it in the night? If the BECM wakes up for some reason you will tell on an auto as the light on the prindle stick will glow if it wakes. Many stories of people sitting silently not moving inside p38s watching the prindle. Makes the neighbours talk but works.
Prindle stick? What's that then?
I think I know how to test for a parasitic draw..check for current draw at individual circuits, some should be completely dead some should have 'some' current draw like the clock on me tratter. Lots when there should not be is bad. Sound about right?
 
Or you can check at battery, pull everything out and watch it as you replace. Think it’s anything over 0.5 v? not done it for while, someone will know? Electrics not my thing but know my way around a P38. Have you checked all Earths....there’s a few especially big one on gearbox.

Prindle Stick is @Bobsticle s.

Park
Reverse
Neutral
Drive
Low
Eject

It’s only a faint glow but a sure sign it’s awake. It draws quite bit doing checks if it’s disturbed.
The battery gonna need drop testing or whatever you can see it’s holding. Pointless testing electrics unless battery is tip top, they will run you round in circles.
 
Measure the voltage across the battery terminals while starting, it should read at least 11v. Any less and it's not a happy battery.
If you've got good ears then can hear a faint hum from the dash which stops when it goes to sleep, you'll also hear a relay click if you're lucky
 
Helluva parasitic drain to kill a big new battery in 24 hours
Interior lights or BECM wouldnt do that
More like heated seats or headlights etc.
Heated seats dont work without key tho
 
Back
Top