Battery Discharge Problem

[KenR]

Hi, someone out there must have had this problem and found the answer! Came out to start the car one morning recently - battery was totally flat, having no sign of problems before. Gave the battery a recharge, and did the obvious checks, loose terminals, checked alternator output when charging looked good at 14.4 volts, everything seemed to be working. Checked everything was off, left car for a while- battery flat again! Called in the AA, who jump started, checked battery and alternator, and said battery no good! Bought new Bosch Silver battery, installed, checked charging ok , checked volts with ignition off, seemed to be slowly losing volts, checked amps across all spade fuzes only 1 with .01amp, found that removing the 110amp line on top of the battery stopped volts falling, and rate slowed with cd multichanger unplugged. However, next morning new battery was flat again!! Oh, I also checked that there was no ac ripple from the alternator!
Anyone had this sort of problem? I am reluctant to go straight to the stealers, as if I knew what to check I can do it myself!!

 

[LEE69]

Boot light on? glovebox light on?

 

[KenR]

Baterry Discharge

Hi, thanks for the suggestion, but I checked that nothing was on first of all. It is something a bit more obscure im afraid!

 

[KenR]

Baterry Discharge

Hi, thanks for the suggestion, but I checked that nothing was on first of all. It is something a bit more obscure im afraid!

 

[Andrewcupra TDI]

had this in an old car , it was the battery that was goosed , replaced with a differnt car a rover V8 thing , (had to match similar width to fit in battery tray was just alot taller , tha\t was job done ,

but the sparky who done it sorted something out with all my subs and amps etc

have you any ICE or is it tatally standard ,

 

[Funkyfin2000]

Ive got this with my golf at the moment, maybe take the car for a really good run....

the interior light was left on when it was serviced, and since then it doesn't seem to hold charge. The battery is only a year old

 

[AntneeUK]

Sounds like it's shorting out somewhere doesn't it?

I vaguely remember someone going on TV last year (IIRC) stating that the AA service men are actually targeted to sell so many batteries a month, so it's in his interest to sell you a new battery, whether it needs it or not. I would never believe an AA guy when it comes to something like that

 

[Funkyfin2000]

Yeah, I might be sending my golf to the autoelectrician soon to investigate as its getting a pain, sorry to hijack anyway!

 

[KenR]

HI, just some more info: the AA man was great, and did not try to flog me a battery - I bought a Bosch Silver from Euro Car parts for £52, which I thought was good.
Back to my discharging problem. I have now found that the discharge is through the fuze for the a/c and radiator fans. The fans work ok as the engine heats up, and they turn off as the system cools, but leave a discharge of about 2 amps throught he fuze. If the fuze is taken out the fans do not turn off so it needs to be there. There is supposed to be a fan control unit somewhere - looks like a relay- but it is not on the relay panel - does anyone know where it lives?

 

[KenR]

Hi, update on my battery problems!
Wired an ammeter into battery positive side, and saw up to 2amps draw with everything off! Pulled out every fuze in turn to find where current was going, and found fuze 16 had more than 1.5 amps. This fuze supplies the Fan Control unit, which in turn controls the rad fans for cooling and for air conditioning. The fans were not running, but pulling the fuze caused the fans to run continuously!!!
Obtained a Fan Control Unit from VWJAUDI who are highly recommended, for £12.99, where the Stealers wanted £101!!
I have now replaced the Fan Control Unit in its hideaway beneath the battery tray mounting plate, and will report later if this turns out to fix the problem.

 

[LEE69]

Nice one for reporting back, that control module does go funny.

 

[KenR]

HI,
An update to say that changing the Fan Control Unit seems to have solved the discharge problem. I still can not find any cause for the Unit failing, but in the current cold spell the radiator fans do not need to come on even in traffic, so fingers crossed that they do not cause a problem later!

 

[777cupra]

I think i have a similar problem, my car seems to be running at a colder engine temp and I don't have battery life for more than about half a day with a new battery. where abouts was this fan control unit, and is it a simple un plug and switch over job?

 

[LEE69]

It is under the battery tray area.

 

[777cupra]

what does it look like?