Avensis Lights Dimming

August 15, 2003

Hi everyone,

Due to my ICE install, when my 2 subs drop the b-line really low all the cars lights dim and even the cars performance is affected. I know this is because of the large amount of power being drawn by the amplifiers. So I've fitted a digital powercap which has helped slightly but I still have the same problem when its cranked up high. Some people have suggested I fit a diesel Battery and alternator as these are suppose to be much more powerful, is this true? if so, can i buy this from the diesel version equivalent to mine (99-V).

Thanks...

August 16, 2003

Getting a higer amp Battery will make no difference when the car is running...but yes, get a beefier alt....which will mean you'd need a beffier Battery anyway..otherwise the Battery acid will start to boil!

but if it's drawing that much power...and you stary sticking bigger alt's in ...then the harness could potentially burn out in the long run.

Vipes.

August 16, 2003

This is basically down to asking for too much power all at once. A higher output Battery is a must because this will be the main backup supply for that required inrush, it needs to get it from somewhere. Of course then a higher output alternator comes next to keep on top of all this.

I take it your supplies for your amp gear are taken straight from your Battery terminals? So what about the negative (earth) Have you fed a seperate negative cable from the Battery to the amp? If you are earthing off the cars body then you are using the earthing cables from the battery which were manufacturer installed and calculated to cope with the cars standard loads. So you either need to run a seperate negative or uprate those earthing harnesses. These can only pass so much current at any one time so this could simply be the reason for the volt drop.

Sort the power cables out first to cope with the excessive load, then do the battery + alternator.

Any probs, e-mail me. I'm an electrical engineer so should be able to help at least a little with my relatively small mind :lol:

:thumbsup:

August 17, 2003

As Sjrainsford says, check the cabling first. Rule of thumb is that 1Farad per 1000W worth of amps should be enough. So if you've got this 1F/1000W ratio sorted than check first the distance between the cap and amps (should be as short as possible - not critical but helps) and check the negative cable. (e.g connection at the amp and and the other end).

I have not heard of any dimming porblems from people having 2kW eq stuffed in their car and running standard batteries and alternator. The high momentary output is realised by the cap and as long as the total current is less than what your alternator's producing you should not need another one.

Good luck

August 18, 2003

Sorry for the late reply, thanks for the really helpful feedback.. Im just in the process of checking through everything that you suggested. The supplies for amp gear are taken straight from the Battery terminals. It is earthed both from the amp to the car body and the Battery.

The amp is maxed at approw 1800W (1000a2 Rockford Fosgate) +a separate Pioneer amp running 6x9s and components. The powercap is a 1 farad rockford fosgate situated right above the rockford amp (the cable runs are as short as possible). I have no idea what the alternator is producing?!

Thanks...