Power Loss To The Car - Someone Please Help...

Exactmax

Active member
Hi,

In the last four days I have been having problems with loosing power to the car. On the first instance, I was driving at around 30MPH, headlights on, heating on, radio on, decided to put the fog lights on and all the lights and electrics dipped in power and then came back to life within half a second. It was enough of a power loss to reset the clock and milage counter. All the dashboard lights came on and then went off!

A few days later, when parking the car, I experienced the same problem (reset the clock, power dipped, dashboard lights all on). The engine keeps running fine during this power loss and once the power loss has stopped, all the dashboard lights go off.

Two weeks prior to this problem I installed a subwoofer into the boot and wired it accordingly. I have spoken to my local garage and he suggested to un-wire the sub from the battery and see if the problem persists. Does anyone have an idea of why this is happening and what causes the power loss problem?

Many Thanks
 
Gotta be to do with the sub wiring, I'd go back and look at your connections in that area very carefully.

Check the earth cable for the battery, and make sure the battery is screwed in perfectly.
 
I'm with Andy and would go to the main battery connections. Check if they are getting hot and then key fuses and earth points. I'd say the amount of current drawn through a faulty connection causes it to drop out.

Given you made a wiring change look at that first.

Beyond that I'd go to an autoelectrician to run his magic on it.
 
It could be your battery is on its way out and not charging properly.

Where are the earth and power cables from the subwoofer connected?
 
Exactmax said:
Hi,

In the last four days I have been having problems with loosing power to the car. On the first instance, I was driving at around 30MPH, headlights on, heating on, radio on, decided to put the fog lights on and all the lights and electrics dipped in power and then came back to life within half a second. It was enough of a power loss to reset the clock and milage counter. All the dashboard lights came on and then went off!

A few days later, when parking the car, I experienced the same problem (reset the clock, power dipped, dashboard lights all on). The engine keeps running fine during this power loss and once the power loss has stopped, all the dashboard lights go off.

Two weeks prior to this problem I installed a subwoofer into the boot and wired it accordingly. I have spoken to my local garage and he suggested to un-wire the sub from the battery and see if the problem persists. Does anyone have an idea of why this is happening and what causes the power loss problem?

Many Thanks

As others have said - work backwards from any electrical alterations you have made. :thumbsup:
 
Maybe your Z4 is angry? Maybe it doesnt like having a subwoofer in its boot and its throwing a temper tantrum?
 
The subwoofer was wired directly to the positive on the battery and the negative for the earth source. I have since un-wired the subwoofer to see if the problem occurs in the next week or so, if it does then I know its not the subwoofer and something more serious... Any ideas why it only happened about two weeks after installing the sub and not straight away?

Is there anyway of checking if the battery is almost 'hadit'? How long should they last anyway? Many thnaks people
 
I've never been into or really understood advanced audio set ups in cars BUT I am certainly not a fan of directly wiring any additional electrical gadget into the car without it passing through a switched supply and protective fuse ie when you switch the engine of power to the gadget (or in your case a sub whoofer) is switched off. Battery life 4-5 years. Halfords will check it for free (in the hope you will buy a new one) and any good garage should do this for you. If not:

http://video.google.com/videosearch?client=firefox-a&rls=org.mozilla:en-GB:official&channel=s&hl=en&source=hp&q=testing+a+car+battery&um=1&ie=UTF-8&ei=ZXZrS4W3B4qg6gPKkamFBg&sa=X&oi=video_result_group&ct=title&resnum=1&ved=0CBAQqwQwAA#
 
AlanJ said:
.................. I am certainly not a fan of directly wiring any additional electrical gadget into the car without it passing through a switched supply and protective fuse ie when you switch the engine of power to the gadget (or in your case a sub whoofer) is switched off
+1 :thumbsup:
 
Alan J is spot on. Nothing should never be wired direct to a battery, but should go through the cars wiring and be taken of an appropriate fuse, for many levels from th esimplest of having a tidy installation, proper fused system and even to it being part of the circuitry that the car shuts down after 15 minutes. If you feel the need for serious current capability put a relay in ad take that from a main power source.

As said you can test the battery at a Halfrauds, but frankly if it's spinning the engine freely and you're not getting the charge light on the dash then I'd say it were still good and the charging system is sound. Try starting the engine with lights and fan on and see if it still does it... I've never heard of cars that are able to freely start then later while driving the current fail due to battery of charging issues.
 
Whats the current draw of your amp?
What size fuse have you got inline to the amp?
What size cable have you used from the battery to the amp, then the amp back to the battery?
have you used decent clamp on connectors on the battery?
Where are you taking the amp switch from?
 
what size amp have you got, depending on the draw from the battery it could be taking too much in combination with the rest of the electrics.

you may consider using a capacitor to regulate the flow of energy to the amp.
 
Thanks for everyones advise so far - this is the subwoofer installed in the car http://www.fusioncaraudio.com/united-kingdom/car-audio-1/active-enclosures-8/enat1100-24-product.aspx and (it has a 15AMP fuse in the amp). There is also an inline fuse fused directly to the battery on the positive lead.

The wiring kit that came with the subwoofer was this one http://www.fusioncaraudio.com/united-kingdom/car-audio-1/accessories-11/acak04e-82-product.aspx#addninfo - the cables to the battery (+ & -) are screwed to the battery terminals using the nuts and washers so there is a clean connection there. The 'power-on' cable is wired from the radio to the subwoofer - thanks to the adaptor bought from New Mini Stuff.

I didn't have this problem with my Mini Cooper S where is was exactly the same install methods. Any ideas? Is there anything I can do myself to check the battery level (a button on the battery or something)?


Thanks
 
could just be that you're drawing the max current from the battery with everything switched on?
 
Should be fine, that wiring kit is way over the top for the amp so no probs there.
I would check the size of the fuse they supplied with the wiring kit as it may be to big to offer any protection to the amp, the inline fuse should be the same as the components its there to protect, check its a 15A fuse.
Other than that check your connections on the battery and make sure that the positive is not grounding out anywhere, also check for frayed cables at the amp side of things.
Out of interest how have you managed to connect 4gauge cable into that amp as surely the cable is massive compared to the connectors?
 
Exactmax said:
Thanks for everyones advise so far - this is the subwoofer installed in the car http://www.fusioncaraudio.com/united-kingdom/car-audio-1/active-enclosures-8/enat1100-24-product.aspx and (it has a 15AMP fuse in the amp). There is also an inline fuse fused directly to the battery on the positive lead.

The wiring kit that came with the subwoofer was this one http://www.fusioncaraudio.com/united-kingdom/car-audio-1/accessories-11/acak04e-82-product.aspx#addninfo - the cables to the battery (+ & -) are screwed to the battery terminals using the nuts and washers so there is a clean connection there. The 'power-on' cable is wired from the radio to the subwoofer - thanks to the adaptor bought from New Mini Stuff.

I didn't have this problem with my Mini Cooper S where is was exactly the same install methods. Any ideas? Is there anything I can do myself to check the battery level (a button on the battery or something)?


Thanks

All sounds OK on the wiring side, but have you actually taken the connectors off ensured they are clean and then well connected? I've seen tight connectors fitted on top of corroded terminals. you've got to go for the obvious on this one to start.

If you don't want to take the battery to be tested put a meter on it both static and then with the engine running. Should be getting 12.x volts static and in the 14+v region above tickover. Once running turn everything on raise the engine revs to say 2k rpm and make sure the voltage is rising to a healthy 14.x volts.

Post what's hapening.
 
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