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Help! Mk3 Golf, Flat Battery, Dodgy Global Closing

Hello,

Some help from the panel please :)

Problem

------- Have recently inherited a Mk3 Golf (actually a Vento) everything is peachy apart from the battery going flat after about a week. The alternator is fine, charging is getting to the battery, and battery has been replaced.

I've done some diagnostics, now could do with a couple of pointers!

Diagnostics

----------- Current Drain when car unlocked: 0.01 Amps Current Drain when car locked: 0.40 Amps

Unlocking the car, the current drain immediately goes down to

0.01Amps. On locking the car the drain stays at 0.4 Amps. Over the course of a week this totally drains the battery. All the doors, boot and petrol filler unlock/lock correctly.

A Clue? Global Closing

----------------------- There is a small problem with the Global Closing - it is impossible to unlock the drivers door without all the windows dropping down at the same time. If you allow the Windows to fully drop, the only way to raise them again is via the key on the drivers door, starting the engine and using the internal window buttons does not raise the windows. I think this could be an important clue?

Could the Battery drain when locked and the problem with Global Closing be related???

I'm quote a dab hand with replacing parts, and going to a VW Garage will be last resort ... all advice gratefully received!

Many thanks

Regards, Steve

Reply to
StevieBoy
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pull fuses till the current drain stops, this will show the circuits involved, from there it must be simple to isolate the cause.

A possible might be a faulty window switch.

MrCheerful

Reply to
MrCheerful

When I bought my Golf, I had a few problems with the central locking and window close system. It turned out to be the control unit in the boot (trunk). Apparently failure of this unit is a common fault and I had trouble finding a second hand replacement. Eventually I did though and it has worked fine ever since.

Before you change the unit though, it may be worthwhile checking the signals to the unit from the door locks. I can't remember which terminals, but locking the door sends a 12 v pulse to one terminal, unlocking sends a pulse to the one next to it. If there's something wrong with the microswitches in the doors, the control unit may be getting the wrong signals. Wouldn't be surprising to find a waterlogged microswitch in a door panel!

Stevieshutts

Reply to
Stevieshutts

Further news, locking the drivers door from the knob from inside the car results in 0.01 Amp drain, whereas locking via the key gives the

0.40 Amp drain.

Sometimes locking via the passenger key results in 0,01 Amp drain, sometimes in with 0.40 Amp drain. Global Closing is all over the shop with both doors. Therefore it does look as if the control unit is kaput.

The vacuum motor for the central locking only cycles for a few seconds, so I guess at least this part is working okay.

Can I disconnect the Control Unit in the boot (when I've found it) apart from Global Close and Central Locking, will it affect anything else?

Dare I ask, how much is a (new) replacement control unit?

Regards, Steve

Reply to
StevieBoy

The control unit only looks after the central locking and remote window/sunroof closing as far as I'm aware, so it should be OK to disconnect it. A second hand replacement cost me £35. I dread to think what VW would charge for a new one.

The control unit is integral with the vacuum pump. If you can hear the pump running, follow the noise.

The more I think about this, the more it sounds like a wiring problem than the control unit. As well as the microswitches in the doors, the other place it could quite easily go wrong is the wiring loom exit point from the front doors. If I remember correctly, there's a plug connector in each footwell adjacent to the cable trunking for the door jams. Try disconnecting them one at a time.

Stevieshutts

Reply to
Stevieshutts

Maybe worth pulling back the rubber outer for the door looms at the hinges & checking for shorts & nicks in the wires. Constant hassle in mine.

James

Reply to
Juper Wort

Thanks chaps, after disconnecting the control unit/pump (found it in the boot) found that there was still a current drain and global closing was still going loopy.

Will take the doors apart and check the microswitches and also the connector plugs/wires for shorts.

Regards, Steve

Reply to
StevieBoy

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