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[Slowmo]

I hope one of you electrical wizards can shed light on my problem.

I have a current drain problem on my 1999 mini-facelift 3L elite estate. This will flatten my battery a lot more quickly than expected. If I measure the current drawn from the battery, with all doors closed, and nothing switched on, then I get a current of around 600-700 mA.

If I disconnect the battery and reconnect, then after a short time the current will be about 40mA, which is what I would expect. If I then switch on the ignition, and then off again, and wait for all the ancillary things to switch off, the current is back up to 500ma+.

All lamps, Radio, Sat Nav and the Muti-display are off. The power sounder for the alarm was removed some time ago, and the connectors tidied away, so it can't be that.

If I remove F6, the supply to the Bose Amp, then the current reduces, but is still 200-300mA. Something must be staying alive when it shouldn't be. I have tapped all relays which I can see, just in case one is sticking.

Anybody have any suggestions as to where to look next?

Peter.

[Andy B]

I take it you have now read the bit about removing the powersounder DaveDND      

[Dave DND]

I take it you have now read the bit about removing the powersounder DaveDND      

Yep !

 

[Kevin Wood]

There is an accessory timer that keeps certain circuits powered for a few minutes following ignition switch-off or door entry. (Window winders, rear lighter socket, interior lights, etc.).

I wouldn't mind betting that's what's causing the issue.

Leave the meter connected for 10 minutes or so with the car shut up and it should go down to a sensible level.

Kevin

[Slowmo]

Thanks for your suggestion, Kevin. The current does fall back after several minutes, but only to the high current which I mentioned.

However, I have spent most of this morning pulling fuses etc. with no effect. But I have since found out what is causing my problem.!!.

The aux power output from the radio (CCRT700) which energises the Power amp, the CD player and the aerial amplifier is staying live when all is switched off.

Together, the auxilliary items take several hundred milliamps. I have removed the radio, and all is well with my consumption.

I shall now have to look to see if the aux power O/P is from a relay or a solid state device. If it's a relay, it may be sticky.

I don't use the radio too much, but I enjoy having the CD, Telephone and Trafficmaster. If I get another CCRT700, will it need to be 'paired' with my car?

Thanks, Peter.

[Dave DND]

Try refitting the radio and unplugging the roof aerial at its base (NOT at the rear of the radio)  -  many have electronics inside which can cause a problem similar to what you are describing due to water ingress

 :-?

[Kevin Wood]

IIRC some head units do leave the aux. output on for a while as this allows the CID/MID to continue to display a warning message. Not sure how long you'd typically have to wait though. :-/

Kevin

[Dave DND]

few minutes - tops !

Should have "reset" and turned off within the time that has been allowed for the car to "settle" before taking current readings. 

Unlikely to be the radio though, something associated with it ? - probably

 :-?

Incidentally, Vectra / Astra / Corsa beesting aerials draw about 600~900 mA when faulty and keep the accessory line of the radio powered which can then cause parts of the vehicle aux / ign circuits to start to power up from backfeeding the radio.

[Slowmo]

Thanks for your input Dave and Kevin. I have investigated the roof aerial and connections look good.

I have now got the radio indoors powered by a Bench PSU. I can report the following:

1)    Power consumption when supplied with 12V, but switched off  -  negligible. Aux and Antenna o/p at 4.5V with no load.

2)    Radio switched on, Current draw about 500mA. Aux and Antenna o/p at 10.8v.

3)    Switch radio off - Current drops to 400mA, then after 30sec drops to 150mA, never less. Aux o/p drops to 4.5V.

It seems as if once the radio has been switched on, the consumption never drops back to negligible. Sounds like it's kippered. What do you think.

On previous radios I have had, the Antenna o/p is just a switched 12V supply. Is this radio different, or is it just faulty?

Thanks, Peter.

[Kevin Wood]

Yep, these radios are just a switched 12v output the same as any standard head unit. Load the output with (say) 1K ohms and it'll probably drop to zero when off rather than float at 4.5v.

Sounds like your radio is not fully powering down. Maybe the firmware is corrupt or has got into a funny state. I have seen Omega head units do odd things like forget their memories or refuse to turn off completely in the past, so I wouldn't be surprised...

Not sure this accounts for all of your current drain, though. :-/

Kevin

[Slowmo]

Kevin - I put a 470R resistor across the aux o/p voltages now 0.2V when off, 9.4V when on.

I think what you said about not powering down properly is correct. Difficult to know where to go from here.

Are all CCRT700s the same (Apart from Bose/non Bose)? If I get another one from here or ebay, will it just drop in? Does it have to be from an Omega?

Thanks, Peter.

[Dave DND]

You can`t just bung it on a power supply - there`s a bit more to it than that - and what are you using for a disply in order to get the boot up seqeunce correct? How are you entering the code, as at the moment, the unit is waiting for you to do something.

As far as the aerial connections I mentioned earlier, I wasn`t suggesting to look at the plugs to see if they were ok - I suggested to UNPLUG them at the base and then try, as only that way can you eliminate the suspected faulty internal amplifier within the aerial base.

[Slowmo]

Dave, thanks for your comments.

In order to eliminate possible problems with the aerial, I have now disconnected it, and tried reinstalling the radio. The result is much the same, perhaps a few milliamps less. The current drain when off is similar around 500mA above normal.

The radio normally runs with coding deactivated, and so the radio comes straight on when power is reapplied. The unit is sitting quite happily on my bench playing Radio 2. It will also happily receive an incoming phone call with voice through the speakers. (No Mic, so no reply!!)

In the car, the unit behaves impeccably, with every function working perfectly.

I have come to the conclusion that some switching device, MOSFET or other, is sort of latching on when powered, and refusing to switch off properly. It's probably connected with the poor/non working of the Aux o/p line(s). Without a schematic I don't see how I can pursue this any further. I will try for a replacement CCRT700.

Thanks, Peter.