Electrical issue?

[Mart2912]

Hey folks, I wonder if anyone can shed some light on this.

Went to start my car after a couple of weeks of it not being used. Battery was completely dead. Keys wouldn't even unlock the car remotely and there was nothing when you turned the ignition on. So I hooked up my battery charger overnight, then started the car first time with no issues in the morning. I decided to go to the garage to get some fuel, but noticed my fuel release button didn't work, so couldn't refuel. Got home and had a good look at it and it turns out:

• Fuel release button doesn't work
• Central locks button on door doesn't work
• Electric mirror controls don't work
• Electric windows don't work
• Remote unlock with key doesn't work

Everything else seems to be ok and there are no warning lights. I don't really know what I'm doing when it comes to cars, mainly just wing it, but I used my multimeter and ran a continuity test on the fuses (Interior fuse box on driver side and engine fuse box), and non of them came back faulty (Well they read 0). The only thing I didn't test was the relays in the engine bay fuse box.

I really don't know whats going on. Could something have been damaged while the car was recharging? I would have thought a fuse would have blown if that was the case? Also, I think the alternator might be on its way out as the battery is less than a year old, yet it will drain after a week or 2, so I'm not sure the alternator is providing enough charge.

This is on a MK5 Golf R32.

Anyone has similar issues? Any ideas what I can check?

Cheers.

 

[andy_mk3]

I'd try a simple disconnect of the battery for a few minutes a d try again. Low voltage can mess things up a bit. If it's reconnected with a good battery then it should allow it all to come to life cleanly.

 

[Mart2912]

Thanks for that. I'll give it a shot after work. How long should I disconnect it for? Around 10 minutes would be enough?

 

[dale1uk]

Did the battery fully recharge? What volts is it reading with the ignition off and what about when the engine is running? Cars can shut down a number of things if the battery voltage is low so I'd be checking that first.

 

[sovietspybob]

Yeah could be the voltage of the battery is still a bit low, low voltage can cause all kinds of weird issues with the rest of the cars systems.

 

[Dangerous Dave]

All those functions go through the drivers door control module which is integrated into the window motor. Check the wiring to the door it may be damaged where it goes through the grommets etc. Also get it scanned by a scan tool that can access all the control modules VCDS or OBDeleven will do this.

It is worth checking the battery voltage as on my MK5 Golf when the battery was on it's way out the drivers door button illumination wouldn't come back on for a few seconds after starting which was likely the control module not getting enogh power during the cranking this stopped happening with a new battery. It did work fine with the engine running with the old battery

If the battery was left flat for a while it will likely be damaged and need replaced.

 

[Mart2912]

Thanks for the replies, much appreciated.

I don't think it's a wiring issue as on the drivers side as the passanger window controls dont work either.

So the battery is at 11.75v idle, and jumps to 13.40 when the engine is on, but it seems to be slowy dropping! Since I mentioned 13.40, it is now 13.29. That is in the space of around 5 minutes. It has then held at 13.29 for another 5 minutes and it is slowly climbing up. Now at 13.31v.

Do you think it's worth just hooking it up to the battery charger a bit more?

EDIT: Ok, it's back to 13.29v. Doesn't seem to go much beyond that before dropping again.

 

[dale1uk]

The battery definitely needs to be back on a charger or ideally a maintenance charger with a recondition cycle. The battery voltage at its normal state (engine and ignition off) should hold at around 12.6v. If yours is only at 11.75 is pretty much still fully discharged. With the engine running and the alternator working you should see up to 14.5v

 

[Mart2912]

Ok cool. I'll stick it on charge. Not sure what you mean by recondition cycle? The charger I use is called Neco Genius5 if that's any help.

 

[dale1uk]

Some maintenance chargers have an option to recondition damaged/old batteries. Having a quick look at yours it looks like it's got a repair setting. I'd be tempted to run that to help recover the cells

 

[Dangerous Dave]

Thanks for the replies, much appreciated.

I don't think it's a wiring issue as on the drivers side as the passanger window controls dont work either.

So the battery is at 11.75v idle, and jumps to 13.40 when the engine is on, but it seems to be slowy dropping! Since I mentioned 13.40, it is now 13.29. That is in the space of around 5 minutes. It has then held at 13.29 for another 5 minutes and it is slowly climbing up. Now at 13.31v.

Do you think it's worth just hooking it up to the battery charger a bit more?

EDIT: Ok, it's back to 13.29v. Doesn't seem to go much beyond that before dropping again.

If you are only getting 13.3-4v with the engine running your alternator may be on it's way out should be over 14v. When you turn the ignition on before starting does the battery light come one ? There is a signal wire to the alternator that tells it when to start fully charging if the signal wire is disconnected/broken the battery light won't come on with the ignition. Mine was left unplugged after a thermostat change and it took me a few months to notice it means the battery isn't charging until the engine is rev'd past 2000 ish revs.

A quick Google of your charger says it has a repair mode use that on the battery, it's a big battery so will likely need close to 24 hours to fully charge with a 5amp battery charger.

 

[Mart2912]

Yeah, the battery symbol shows on the dash until you turn the engine on, then goes off.

I'll leave it charging until it shows a solid green, then I'll run the repair.

 

[Mart2912]

It's now fully charged. It was reading 12.56v. But still no luck. One thing I've noticed, when using the remote to lock/unlock the car, the interior lights come on and I hear a click sound coming roughly from under/behind the steering wheel. Also I can unlock/lock the boot, but other than that still have my original issues above. Car's going in the garage tomorrow. Should be interesting to see if it will make it with the fuel level. I will have to go full eco mode and drive 50 in a 70!

 

[Mart2912]

Well, got the car back from the garage after a service. Didn't fix the problem, he checked all the fuses, but the guy reckons it is an issue with some sort of control/power module as he managed to open the fuel tank using a laptop and software. He said he could order a new one at £400 a pop, but they apparently ask for the cars vin, which means you can't return the part if it turns out to not be faulty?

So now I have to get it in to a car auto electrician to tell me what's going on.

On the plus side, I have managed to fill the fuel tank...

 

[Mart2912]

Well, looks like the problem has been fixed!

Took it to an auto electrician and initially, they said the door locking mechanisms would need replacing (At a cost of £250 each from VW!!), but they would take pictures of the part numbers so I could look online myself. Second hand ones were going on ebay for like £30-£40 each, so I thought no brainer. But an hour later, they said it was it working again, after disconnecting and reconnecting both of them. I wouldn't have thought the electric mirrors and windows would be connected to them, but they were! So the battery going flat must have just knocked them out somehow. They did say they have seem similar before where it works for like a week, then the problem comes back so fingers crossed this is sorted.

They charged £180, so if this remains fixed then it's a lot les than I thought it was going to be. I swear sometimes with this car it's a love/hate relationship. When it's working, it's great fun to drive hearing the 3.2l "v"6, but when it breaks, I just want to get rid of it! From an economical point of view, I really need to get rid, but I don't think sensibly when it comes to cars.