Battery drain-Help needed

I have had a 2003 TF for since 2013 and it's recently started flattening a good battery overnight. With an ammeter in series with the negative terminal of the battery there is a 4 amp drain with everything turned off, doors closed etc. The fault finding process shouldn't be too bad I thought, however due to a back condition makes it difficult for me to do. So a local garage that specialises in repairs on mini's and MG's said they would take a look. After three days they don't seem to have got anywhere. At £60 +VAT and hour I have opted to collect it on Friday otherwise I might need to remortgage the house to pay for it. It's up to £300+ so far without any success. Can anyone recommend and one in the North West who might be more experienced in this kind of fault. At least I can use the car but need to remember to disconnect the battery overnight.

Try unplugging the ECU, there is a relay in there that should be live for about 10 minutes after switch off but sometimes stick on.

Thank's, I'll try that. Would you expect a 4 amp draw during the 10 mins before it times out?

4 amps at 12V is about 50 Watts. That is one big drain, and I would be concerned something might overheat and burn out!

My suggestion would be a diode in the alternator failed short.

Not sure how much work you are able to do, but disconnecting the big fuse in the engine comprtment might show this.

Also windscreen wipers can cause big drains if they seize up. Do they work?

Fan motor?

Not much else can drain 50 Watts without showing it.

Pulling fuses one by one untill fault dissapears is the best way to look at this problem.

Where in the northwest are you?

Yes 4 amps is quite high. I get the car back Friday from the garage. I did suggest to the garage it might be the alternator but they didn't seem interested. From what I have read there is a 60A fuse in the boot which if pulled will eliminate or confirm the alternator. I am in the South lakes area (Ulverston).

If there is anyone in the NorthWest who can look at it I can travel ok as it's charging ok just drains overnight.

Just out of interest is G0RSQ your Amateur Radio callsign? Mine is G4BDE and the wife is G4FHA. Though not been active for quite a while.

Wrongway wrote: At £60 +VAT and hour I have opted to collect it on Friday otherwise I might need to remortgage the house to pay for it. It's up to £300+ so far without any success.

I think I would avoid a garage that charges for 5 hours of labour for failing to find the source of a problem like this!

My Mercedes Benz Commercials main dealer charged me for just one hour of labour to resolve a bizarre dashboard 'lightshow', multiple error messages and repeated breakdowns in my Vito. The cause was apparently a short to ground in the CANBUS behind the instrument cluster. Mind you, they charge £132 per hour!

Just a quick update on the battery drain problems. I picked the TF up from the garage last Friday leaving them still scratching their head and no where near finding the problem and me £288 lighter. After a bit of researching and forum advice I pulled the 80A fuse and the drain disappeared confirming the alternator. Well one or more of the diodes. I had the alternator changed today and a new belt fitted with just a couple of hours labour charge. Glad it's back on the road and thank's for the help here.

Shows how poor the garage was!

First suggestion I made here (before you went to the "other side" :whistle:) was alternator fault (purely due to the size of the drain), and quick way to test.

Pitty garage didnt think the same way before taking your money!

You and a few others who suggested the pulling the fuse to prove the alternator as the problem was the first thing I did as soon as I got the car home. Within 10 mins I knew. It's a shame I didn't post before taking it into the garage. I did pass suggestions on to the garage at the time but I got the impression they listened but ignored as they seemed fixated on the battery being faulty. Anyway. Glad it's all sorted, the help and support was appreciated.