landarc

Hi. I am new to this forum. Here is my situation that has been plaguing me for 4 years:

I purchased a used 98 GS400 with a system in it already. I have little to no car audio knowledge. I have had a professional car audio shop look at it just visually and they say it was professionally installed. These are the main components:
• RED TOP battery with a fuse. (see pic)
• I have also grounded it to the body of the car. (see pic)
• There are two amps totally 800W – one 500W and 300W. The amps are both by Precision Power.

When the system is on, the green power light on the 300W is fully bright. The 500W one is dim and that one powers the sub. The Sub is a Alpine Type R 10”. (see pics)

I changed the alternator about 3 years back on the recommendation by the professional audio guy. The alternator is 100AMP. Since I changed the alternator, I am still having the same problem. I think it was pointless and a waste of money.

Now when I play my system during the day, the audio will eventually cut out when:
• The electric fans turn on for the radiator
• When there is stop-and-go traffic and the brake booster recharges (this is normal)

The audio comes back on when:
• Once the fans turn off
• Once I get moving

When I play my system at night, the audio will eventually cut out when:
• The HID headlights turn on
• The HID headlights and fog lamps turn on
• The seat warmers are turn on in the winter

The audio comes back on when:
• The HID headlights are turned off
• The HID headlights and fog lamps turned off
• The seat warmers are turned off in the winter

I am assuming that the car loads are too great. The car will sucks all the juice it needs to remain operating at the expense of the audio. CD keeps playing until the car takes what it needs and then the audio is back on.

I am not sure how old the Red Top Battery is either. I am saying at least 6 years. It seems that maybe the battery is being drawn down faster than it can be charged. The car starts fine. No dimming of my headlights either.

What should I do?
• Should I upgrade to a Yellow Top due to the amount of power my system requires? Or a Blue top?
• Should I get a 1 farad capacitor?
• Is there something I am missing?

Please help! Thanks.

Sikk Nation

iTrader: (1)

Get a multimeter and check your voltage across the battery terminals with the car off. and across each amps power wires. If they aren't within .2V then you have a grounding issue, or a poor connection on the power wires where they are split between the 2 amps. If one amp has the same voltage reading as the battery and the other has a lower reading. Also sign of a bad ground. or bad power connection. If the power wires are connected to a fused distribution block, then one of the fuses is probably partially blown. It will look perfect from the outside, but solder in the caps will have melted leaving a really poor connection (getting EXTREMELY common with cheapo fuses these days) If all that checks out.. start the car.. keep all acessories off and check your voltage. At the very lowest at idle with no draw, it should read at least 13.4V. then get someone to rev the motor up a little. You should shoot over 14 volts.. If not. Check the engine to chassis ground first and make sure than cheapo braided strap is still there and not corroded away.

If you haven't found the problem by this point. Run a ground grom the engine block to the neg battery post. If you still have an issue, go to canadian tire and they will doa free alternator test for you.

godzilla1978

I agree it definately sounds like you've got a large voltage drop somewhere. The most audio equipment will turn off if the voltage drops below 9-11 volts. It sounds like the equipment it self has the problem because if it was from the alternator your light's would dim very badly, the fans would slow down and your car may even stall. You still should have it diagnosed properly though because it could be a few things adding up into one large problem. Murphy's law is always in effect!

landarc

Well I got a multimeter and checked the voltage with the car off, 11.85v. Power to the amps match. Turned car on, no accessories on, 13.5v and the amps match. So power is going and there seems to be no grounding issue. I also inspected the fuses and there appears to be no problems with them. No burn out marks, still look brand new. I still have to get someone to rev the engine to see if battery will read over 14v. I will get Canadian Tire to run an test on the alternator. The alternator is supposed to put out 90amps for my make of car and engine size. I will also get a 0 guage wire and ground the engine to the negative post.

I have posted the same problem on the audio section of Club Lexus and one guy says that if the alternator checks out, then it may be the battery. See below:

Few things that you are missing. Honestly the stock gs alternator is 90 Amps why upgrade for a measly 10 amps? Sounds like somebody might have been bs'ing you. First thing that I would do is go to an autoparts store, Autozone in US offers free battery and alternator testing, I have no idea if there is anything similar offered in Canada but you need to run tests to check the battery and alternator.

I currently have 2 amps one pushing 900 watts Rms to 2 12" Alpine Type Rs and a 600 Watt 4 channel to my interiors and I my light dim only when I am at a stop and the system is cranked all the way up.

At rest your battery should be reading 12.6 volts not 11.85. Your battery might be on its way out.

Getting a capacitor will not help as it seems like your alternator doesnt have enough juice to charge your battery. Like I said get your alternator checked, if it is deemed good next step is to see if the battery is the culprit which to me sounds likely, and get it replaced.

Does this sound plausible?

Will update.

Thanks for your help.

Sikk Nation

iTrader: (1)

yeah your battery should read 12.66V with the car off and no load.

Also your fuses can visibly be 100% perfect and be blown, thank you cheap chinese crap solder joints.

It definately sounds like your battery is the root of the issue though. Go to canadian tire and get a free battery test done.

landarc

Well, I bought a new Yellow Top battery and the car and the audio run flawlessly. All it needed was a new battery. I have been living with this problem for 5 years and now it is fixed. Thank you for your help!