I'm not quite sure if this is the best Stack for my question but I will try. So from some time I noticed that in my car when engine is turned off there is still quite huge power consumption which causes after 3-4 days I cannot start the engine. After some measurements I noticed that radio consumes too much power after I turn off engine. What is more this radio (blaupunkt) is damaged and it doesn't insert the cd and by this problem the message "Note: CD error" pops out on the screen from time to time.

And now my question: is it possible that this "cd error" problem can cause some variations in my radio while engine is turned off?

I'm asking because I would like to know if there is something I can do before I decide to give it to some specialists.

Thank you for any help.

EDIT: So today I did measure it again. Firstly it showed again 0.8A then we decided to turn off radio with its button. When we hit the button the value 0.16A was shown. So we were thinking what is still consuming power. After that we decided that we will wait half an hour and then probably it will go into sleep mode. What is funny, when we came back after half hour the value 0.64A was shown! Simple math and we got 0.8 - 0.16 = 0.64! Somehow when the car went into sleep mode the radio started to consume power. Now I am sure that only radio is someway broken so during the week I will go visit some specialist so they can repair the radio.

Thank you for all your help.

  • When both car and radio are off, what is the current draw on your battery? – Zaid Nov 3 '15 at 9:43
  • So when I turned of my engine it showed 0.8A - I know it's way too much. When I pulled out radio's safety-valve (is this the english word?) it showed 0.18A. And this is still too much but I think that if I wait about 20-30min then it will go down when everything would go 'sleep'. – wawek Nov 3 '15 at 9:48
  • I think you mean "fuse". 0.18 A is still quite high. – Zaid Nov 3 '15 at 9:51
  • Yes I meant fuse :) I know it's still too high but what I read is the whole network switches to sleep state after about 30minutes so I hope it will drop from this 0.18A after this time. – wawek Nov 3 '15 at 9:55

Based on your clarification in the comments, pulling the radio fuse drops the current draw from 0.80 A to 0.18 A before the car enters sleep mode.

You may want to check if there is another fuse that drops the current draw further after the car goes into sleep mode. That should help you determine if there is something else that is drawing current unexpectedly (a circuit that is closed when it really should be open).

The other, more time-consuming, option is to actually inspect the car wiring.

  • Hmm you're right but this car model has rather not a lot of electric modules which could consume much power. I don't even have an alarm so there are just: radio, inner lamp, clock and central lock which could consume power after turning off engine I think. – wawek Nov 3 '15 at 10:19
  • "another fuse" -- the radio will have 2 of which only 1 should normally see any power when the ignition is off. As it's an aftermarket radio it could have been wired with both fuses on the permanent live (I've done this in the past, adding a switch) – Chris H Nov 3 '15 at 13:15
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    With ~3/4 of the current going to the radio any other drain is going to be hard to find. I doubt it's a short as it's drawing <0.2A so is >60Ω. – Chris H Nov 3 '15 at 13:18
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    @ChrisH I agree, it is not going to be a short, something is on when it should be off. – HandyHowie Nov 3 '15 at 13:39
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    @wawek : Your comment made me realize I made a silly mistake. You should really be measuring current after the vehicle is in sleep mode, not before. I apologize for the confusion. – Zaid Nov 4 '15 at 8:04

I would disconnect the stereo by removing the connectors from the back of it and see if the problem goes. If that fixes it, just get another stereo from a breakers yard.

  • If I understand you correctly you mean that I should pull out radio and then disconnect some wires which are responsible for my cd reader? – wawek Nov 3 '15 at 9:51
  • Yes. You should find maybe one or two connectors you can just unplug the whole stereo while you isolate the problem. – HandyHowie Nov 3 '15 at 10:07
  • ...or even simply pull the fuse which provides power to the stereo. It may be more accessible and easier. – Steve Matthews Nov 3 '15 at 11:19
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    @SteveMatthews The only problem will pulling the fuse is that stereos usually have permanent and switched supplies and the fuse may also support other functions of the car which may then confuse the diagnosis. – HandyHowie Nov 3 '15 at 12:02
  • Better than returning to a car that doesn't have enough power to start though. If it were me, I'd pull the fuse to save the battery and then it's easy to pop back in so I can have the radio on whilst I drive. – Steve Matthews Nov 3 '15 at 13:29

With the radio disconnected (either fuse(s) or prefereably connectors pulled) it's worth waiting some time to see if the current does drop.

Does the courtesy (dome) light come on when you turn the engine off? It doesn't in my Transit of a similar age which uses many of the same components in relevant systems. In particular the central locking module is common to most Fords of a similar age and is responsible for the interior lighting as well (IIRC, I haven't looked at the wiring diagrams for a couple of years). I reckon if you disconnnect the central locking module as well as the radio your current draw will drop much further.

If you're drawing 0.18A a fuly charged battery should still be able to start the engine after several days, but it should do better than that. I suggest that a problem with the radio is a major factor, but that your battery isn't up to much any more -- is it the original?

I propose:

  • Test with the radio disconnected. At the very least you should get more than double the time before the battery flattens.
  • Check the current drawn after an hour or so.
  • Consider replacing the battery.
  • Thank you for your answer. Battery is rather good because it was bought in December and when I measured current it showed 13.1V. I will have more time in the weekend so probably then I will spare more time for measurement and analyse. – wawek Nov 3 '15 at 17:21
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    The battery should be fine in that case, though they never fully recover from being flattened to the point where they won't start the car. The full voltage seems to be similar on a problem battery, it just drops much faster. – Chris H Nov 3 '15 at 21:03

I had a similar issue that turned out to be a shorted light bulb. It was one of the small running lights on the front sides of the car. I kept blowing a fuse every 20 minutes or so and so had no headlights. Putting in a larger fuse meant that I could drive a few minutes longer before I lost my headlights. I only found the problem because I noticed that one of the small lights was out. When I removed the "dead" bulb, the short went away and I stopped blowing fuses.

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