Battery going flat on Peugeot 306

[ragandstick]

Can anyone help. My friend's 306 battery is discharging over 3-4 days and it is a new battery. I have checked the current drain with the ignition off and there is a draw of 0.16 amps. If fuse no 8 is removed then this disappears. However this fuse supplies several things including the engine immobiliser so the car cannot be run when it is removed. Does anyone know what the immobiliser current drain should be, or does anyone have any suggestions? Many thanks Dave Tedd

[Ricky_M]

My old 306 had a siren isolation switch for the alarm and unbeknown to me the headlights used to flash all night every night.

Worth a try.

[freecar]

You're not supposed to leave the fuse out and problem solved!! You're supposed to fix whatever is now broken causing the drain. Although leaving the fuse out would be my first solution!

I would assume that the car kept a charge in it's battery for more than a few days before? If so you need to check each component linked to that fuse as one of them is broken and drawing current away.

I would hope it's not the immobiliser as this might be difficult to remove and still be able to run the car! I would hope that as the car is drivable the immobiliser is fine!

What other things does this fuse serve?

[Old Merc]

I take it you have checked the boot or glove box lights are not stuck on? The alarm would be the best bet.The siren is inside the N/S/F wing and gets full of water,never makes a noise but the head lamps flash.

[ragandstick]

Thanks for the replies. I have now found that fuse no 8 is in fact not a fuse but a shunt so it will probably feed several other fuses. Have checked boot light but not glovebox so will do Thanks Dave Tedd

[torqueofthedevil]

check head unit supply

[ragandstick]

Am still working on this one. What is the head supply unit?? The fuse which stops the current drain is number 14 and this supplies the central locking, the audio unit, and the Alarm ECU. Anyone have any ideas on what it might be? To separate these 3 items out will not be easy as the wiring at the back of the fusebox is very complex.

[ZeeTacoe]

how old is the 306 and which of the 3(or 4) fuseboxes does it have?

Because I think only the mk1 will have the alarm switch behind the head light.

[Diag]

If the fuse you mentioned is a shunt then the fuse box is actually a module and the car has a CAN network. With a CAN network modules will cause a drain until they go asleep so you need to check the drain after this has happened. Not sure how long on that model but probably at least a half hour. Anytime you connect or disconnect something the network will wake up and so cause a drain.
160ma is not a huge drain but I would expect the correct level to be 20 or 30.

[ragandstick]

Thanks for the replies. The car is S reg and the fuse box has a shunt in the centre. You may be well be right about the CAN. When I first connected the ammeter it read 20ma and so I disconnected it and then reconnected it and it read 160ma. So maybe it is something else? Any ideas?

[Simon says]

A 98 306 is not on CAN

[derekcruickshank]

I am currently experiencing this same problem with a 98 car. Did you solve it?

Edited by derekcruickshank on Monday 10th January 00:53

[ragandstick]

HI - sorry to say that the problem has not yet been solved and the car has been out of use as the owner has been in hospital.

[derekcruickshank]

Sorry to hear that. Hope they get well soon.

I suspect my problem may be the alarm siren. It has rechargable batteries in it which are charged from the main battery. Water gets in to the siren and casuses problems with these batteries and the siren.

I have a red LED permanentlly on on the dash to show there is a problem with this siren.

I will investigate further and post back.

[derekcruickshank]

Seems the Siren was to blame. Disconnected it and the drain on the battery reduced to 0.01A.

Car starts and runs fine with the siren removed. The Siren internal batteries can be replaced and descriptions on how to do this can be found if you search on 306 alarm problems.

The siron can be found under the off-side front wing in front of the wheel. Its easy to get to. Remove the wheel, remove 2 star screws at the bottom of the plastic wheel arch cover, pull back the front section of this cover to gain access and the Siron is visible right behind the side section of the bumber.

Hope this helps you and others with a simmilar problem.

[ragandstick]

Many thanks for your reply - as soon as my friend is up and about I will have a look at the siren and let you know the result.