Need Help

[ukazn]

My car electrics keeps dying out on me, Basically with the system I got when my car is idling and the system is playing, the volt meter drops drastically from about 13.5V down to 9V. When it reaches 9V the system shuts down and the car stalls. I find myself having to rev the car at about 2000 revs just to keep the voltmeter reading up.

I think it could be an alternator problem, what do you guys think?

[bam-bam]

Definately check the alternator output side of things!You've done things right by using caps to cater for any transient bass drops which could cause voltage loss. The other thing to mention is Battery age,type etc?? If for some reason the Battery is not retaining charge properly it could be that your alternator is actually trying to power not just the car's electrics,but is attempting to feed the sound system also!

Chances are it's A Battery shortcoming.

Perhaps look at upgrading to a larger capacity Battery -if the alternator IS charging at its correct rate this should be more than adequate for powering a system of this size AND feed the vehicle's electrical needs.

I'm no expert,but thats where I'd start!

Hope its sorted soon...

Regards,

Gav B)

[ukazn]

Thanks for the suggestions gav.

I also forgot to mention that the Battery is less than a year old and is bought from lexus dealership. I've also noticed hat upon starting the car it takes a while for the engine to start, feels like the Battery is weak. Does this mean the Battery is not holding a charge or the alternator is not charging the Battery.

[Bazza-old]

Thanks for the suggestions gav.

I also forgot to mention that the battery is less than a year old and is bought from lexus dealership. I've also noticed hat upon starting the car it takes a while for the engine to start, feels like the battery is weak. Does this mean the battery is not holding a charge or the alternator is not charging the battery.

from past experience (not lexus )

when the alternator isnt charging a red light appears on the dash display

whip it done to a local auto elec shop will only take mins to check

just my 0.02p worth

[Monster-Mat]

do you have capaciters in the system to store charge...as has been stated, these act as a cushion for the cars electrical system

[ColinBarber]

When I brought a new Battery from Lexus it came with a two year warranty so if your problem turns out to be the Battery you should be able to get it replaced.

[ukazn]

The capacitors are there to store charge in case of any heavy bass lines. Whenever there is a bassline the reading from the digital display drops and then charges back up again. I've noticed that when the car is moving and the engine is revving the voltage reading in the capacitors charge up really quickly. When I'm stationary the voltage will drop slowly charge back up but not fast enough for the next bassline.

Will check at auto-electrician if it is an alternator problem. If it is how do I stand with getting it replace or repaired under warrenty?

[Monster-Mat]

i wouldnt say its a problem with your alternator, i bet its working perfectly ok for a std car.........

the problem is, it isnt upto the requirements now you have a power sapping system, try and find an alternator that has a higher output, or consider fitting a split charger

[ukazn]

I considered trying to get a split charging system put in but would it not make a difference cos if the alternator is struggling with just keeping the charge up on one Battery it would not have a chance with two. I'm all confused now.

I don't really want to fork out more money on an upgraded Battery, second Battery and an splitcharging system if that is the problem.

Its wierd I have friends with much smaller cars and a lot more powerful system yet they still have no probs with their power supply.

Also out of curiousity, If I wanted to upgrade the alternator would I have to buy one specific to the IS200 or can I take one from a say GS430 and put it straight into the IS.

[DUNCAN]

Ukazn,

You haven't told us if the car's voltage performs as it should with the music system off!!!

Does the volt meter on the dash show an increase in voltage when the car is running ?

Whats the ampere hour rating of your Battery ?

And how many amps is your sound system pulling from the Battery ?

[ukazn]

Ok, I don't know much about this stuff so here it goes,

When the system is off and the car is idling the capacitors read a regular 13.6, ocassional 14.2. The voltmeter on the dash reads about a little over 12V I think.

The Battery was bought at lexus dealership, Don't really know what the APH rating would be.

Not sure how many amps the system is pulling, all I can tell you is that amp is running at 500wrms at 1ohm and there is a 40amp fuse on the amplifier.

[james2210]

This might sound like a primative idea, but have you tried leaving the stereo switched off and then going for a nice long drive-say 40 miles or so, in order to see if the bat tree is charged then? You could put your walkman on if you can't stand driving without any choons. Might be a good idea to pull the fuses that feed your flux capacitors just incase they are causing too much drain. If you have a standard voltmeter or multimeter, you could put this on your Battery terminals and check the voltage when the car is switched off -vs- the voltage with the engine running. The reading should obviously be a few volts higher, but if it's not then the alternator might be iffy. Might also be worth checking the amount that the voltage drops with the hifi running, just to see if those caps are doing the job or if the Battery is still taking the full hit.

Don't forget that in this hot weather, the AC puts quite a large electrical load on the Battery so if you're idle for long periods with the AC running and large kicks in your solobarics, the Battery is bound to take a pounding.