Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: scottambrose on 03 November 2012, 09:38:11

Title: continuing battery drain
Post by: scottambrose on 03 November 2012, 09:38:11
still going flat each week. today it had 11.3 volts but still started fine.
so its not fuse 7 as i thought or infact any interior parts.
the fuse box that sits on the battery has 5 fuses and the middle 80amp fuse in the block of 3 is the circuit causing the drain i think. which doesnt appear to run anything inside the car.
anyway i can find out whats on that circuit?
the only other thing i noticed was that the plunger that senses if the bonnet is open or closed wasnt plugged in. that wouldnt make any difference would it?
Title: Re: continuing battery drain
Post by: RobG on 03 November 2012, 10:19:07
FV1 (80 amp) - ABS and traction control
FV2 (80 amp) - Main Engine Relay and glowplug timer ******
FV3 (30 amp) - Motronic Control Unit 
FV4 (80 amp) - Ignition switch
FV5 (80 amp) - 1,6,7,10,20,25,27,29
FV6 (80 amp) - 5,12,17,24, 33 (air con)

****** As yours is petrol it won`t have FV2
Title: Re: continuing battery drain
Post by: scottambrose on 03 November 2012, 11:54:10
thats great i would says its fv5 but what do those numbers mean is it the fuse numbers it leads to under the steering wheel?
Title: Re: continuing battery drain
Post by: dbdb on 03 November 2012, 12:23:15
11.3V for a 12V battery tested with no load on it is exactly zero percent charged, ie completely flat.  It would definitely not start your car.  To test the true voltage of a battery you need to take it off load - disconnect it.  Then wait at least 10 minutes for it to settle, ideally an hour.

If the settled voltage is say 12V your battery is 45% charged which is not very good.  Ideally it should be at least 12.5V (80% charged).  If its regularly draining below 50% it will not last long.  After establishing the real drain, first thing is are you certain the battery is not self draining.  I know you've tried 3 batteries but I'm not sure whether the other two were old ones.  A duff battery will self drain significantly, easy to test - take the battery out, fully charge it for a few days then leave it a few days. It should stay above 12.75V.

If there is a component caused drain the tester Entwood recommended is ideal for you simply plug it into each fuse slot. £10 on ebay, search for 260597798106.  Alternatively get a DC clamp tester as Dave DND said, DC ones hard to find but £26 on ebay - 170868801373
Title: Re: continuing battery drain
Post by: scottambrose on 03 November 2012, 12:53:12
ok thanks. with ref to fv5 if i disconnect it. the car wont start but none of the fuses listed against fv5 look ignition related. and also with all the fuses disconnected that are on fv5 theres still a drain. the batterys were all new ones