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big 3, battery, alternator still dimmingPrinted From: the12volt.comForum Name: Car Audio Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc. URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=111373 Printed Date: July 18, 2025 at 3:31 AM Topic: big 3, battery, alternator still dimming Posted By: javisam376 Subject: big 3, battery, alternator still dimming Date Posted: February 07, 2009 at 10:43 AM Hi, I am going to make this post a little bit long because I feel I need to include the whole picture to be able to get some help... but in a nutshell I have a 380RMS amp with a 1.0 farad capacitor, got new battery, new alternator, big 3 and the lights still dim when the volume is a little bit above the middle point (30 or plus of 60 available).... What I have is: Car: Dodge Stratus 2003 SE 2.4L Deck: Pioneer DEH-P3500 (https://www.crutchfield.com/p_130DEHP...ures_and_specs) Amp: Sony XM-ZR1852 (https://www.walmart.com/catalog/produ...uct_id=9907093) Capacitor: TKO Audio BH-CAP18 https://www.online/CarAu...roductid=19831 Subwoofer: 12'' Kenwood KFC-W3011 (https://www.crutchfield.com/S-Jf7GL39...KFC-W3011.html) I am using 4 AWG wire for the amp and the big 3... with a 60amp fuse for the amp and a 150 for the one from the amp positive to the batt positive... The history is this: I started by getting my amplifier, subwoffer and a 3 way speaker installed... lights started dimming...i went back with the guy who did the service he told me i needed a cap, so i got the 1.0 farad... didnt' do anything... take it again and he told me my electrical system was bad, that i needed a battery and possibly an alternator... a month later i got the battery... nothing... another month later a 120A alternator... nothing happened... started to look around on the web and found out about the big 3 upgrade... went back to the guy and apparently he never heard of that... he even told me to get my amp rewinded (according to the guys who rewind i can only get about 20 more amps for the dodge stratus).... anyway, just did the big 3, 4awg all the way, alt positive to batt remote terminal positive (my car has the battery in front of the front wheel), remote terminal positive to batt positive, batt negative to ground, ground to engine chassis (one of the bolts of the alternator)... i have some pics of my system (The blue circles are the new wiring, the yellow ones are the stock wiring): https://img16.imageshack.us/img16/834...ositiveyr5.jpg Positive alternator to battery positive https://img16.imageshack.us/img16/910...oenginewp9.jpg chasis to engine wire... https://img27.imageshack.us/img27/755...ositiveqd1.jpg Battery positive to alternator positive https://img16.imageshack.us/img16/904...ochasisof3.jpg Battery negative to chasis https://img27.imageshack.us/img27/6262/ampyh3.jpg Amplifier wiring https://img16.imageshack.us/img16/5072/ampgroundpa6.jpg the ground for the amp and the cap https://img16.imageshack.us/img16/4227/capacitorbn2.jpg Capacitor wiring The guys in my regular shop are telling me to get a second amp... but the rule is 1.0 farads for every 1000RMS, right??? therefore a 0.5farad cap should be enough for my configuration??? I got my alternator online, i guess there is always a chance to get screwed and not have the 120amps I paid for... how can i check that??? I took it to autozone and they told me that it was throwing 6 amps... can it run with only 6 amps???... i checked for amp meters online and they are about 250$ and plus... there a few ones below 50, but are they accurate??? Are they cheap because they suck or because the other ones have extra features that i shouldn't care??? I also got one of the baterry meters that plugs in the car lighter... my volts range from 13.9 to 14.8 when the lights dimm... the lights in the capacitor blink, does that mean the energy from the cap is being used when they blink???? I am starting to get desperate... my plan was to get the amp and subwoofer, then get a cool deck (with ipod control), then component speakers... at this point i believe i have already thrown almost (if not more) than twice of what i paid for the amp and subwoofer and i cannot pass from the half point in the volume unless i disable the woofer... i am starting to seriously consider to take the whole thing out and sell it on craigslist to get at least a few $ back... please, i need all the help i can get... does anybody know a place where i can get that checked on Rochester, NY??? the guys who did my amp installation seem not to know about the big 3 (they didn't even bother checking my current wires) and they want me to get a new alternator (again)... they guys in the regular shops (midas, monro muffler, etc) seem not to know about car stereo and they told me to get a second cap.... what can I do??? I already rechecked that the grounds are in bare metal and disconnected the capacitor... Could it be that the amplifier is consuming more energy than it should (my volts don't drop below 13.9, most of the time aroung 14.3-14.8.... thanks... Replies: Posted By: attack eagle Date Posted: February 07, 2009 at 9:52 PM that sounds about right, those oversized alternators do not always have MORE output at low rpm and idle, they often have LESS.
I think a better OEM alternator would have been the way to go, and might fix your problem. the other thing is TURN THE GAINS DOWN. TURN THE VOL KNOB COUNTER CLOCKWISE. it is very easy for people to get overly agressive with the volume/ gain/bassboost knob trying to make the bass louder/harder etc. It is entirely possible in these situations for a 350w rms amp to actually draw MORE amperage if you are driving it into clipping during the transient compared to a 750w rms amp with the gains set correctly. does the problem disappear at higher rpm? Does it disappear when the gain is turned down? does it disappear when you turn off all eq bassboost MX loudness etc? ------------- 92 BMW 525iT Black on Black Posted By: whiterob Date Posted: February 07, 2009 at 9:55 PM Wow, I'm surprised you are having that big of an issue with such little power.
You have pretty much done all of the recommended solutions for attempting to fix your problem. I'll give you a couple of things I can think of off of the top of my head. First, I know you checked you ground already but I think you should try measuring the resistance of your ground. From the picture I think you could possibly not have the best connection. The metal you connected it to may have a coating on it. Use the link below, it is a sticky that will tell you how to do this. https://www.the12volt.com/installbay/forum_posts.asp~TID~49445~PN~1 If that isn't your problem then it may not be a problem with your system but with the wiring for the rest of your car. If I remember correctly, that car has a small wire going from a terminal under the engine to the fuse box. You could try replacing that wire and it may help. Your voltage is good from what you said so I would think it could be something simple such as replacing that wire. A second/bigger cap won't help your problem. Those are two fairly simple suggestions I can think of. I will be interested in seeing what other people come up with to help you solve your problem. Posted By: attack eagle Date Posted: February 07, 2009 at 9:59 PM btw .4 volts drop is MORE than enough to make the lights flicker because the lumens produced by the filament are very voltage dependent, and the eye is very sensitive.
try revving the engine to 2500 or 3000 rpm... still ahve a problem? what about 1500? if no to both then you need to gear up the alternator to run faster at idle. or install an idle boost circuit and solenoid for parking lot showing off or jsut turn it down. alternators do NOT put out max voltage at idle speeds (probably lack of airflow would overheat em if they did), Oem ones usually start making a significant portion of rated power just off idle, aftermarket HO usually need 2-3k rpm to start making more power than the one they replace. Could also jsut be a burned out leg on the rectifier on your HO alternator too. In that case they often show good volts but no amps. YOu got a spec sheet on it's output to compare it too? ------------- 92 BMW 525iT Black on Black Posted By: javisam376 Date Posted: February 10, 2009 at 4:52 PM It goes away if i put the amp so low that it will be the same as not using it at all... and it happens at idle as well as high rpms... Posted By: javisam376 Date Posted: February 10, 2009 at 4:56 PM yes, it happens at high rpms too.... the only information i have about the alternator is: USA Industries Alternator2001-2006 Dodge Stratus USA INDUSTRIES 120 AMP REMANUFACTURED ALTERNATOR, CORE CHARGE APPLIES -- This Direct High Quality OEM Replacement Alternator Features Zinc Plated Pulleys And Fans, New Heavy Duty Front And Rear Bearings, Hardware And Insulators, Regulator And High Amp Welded Rectifiers, It Meets Or Exceeds OEM Specifications, A Manufacturer's Warranty Is Included attack eagle wrote: Posted By: attack eagle Date Posted: February 10, 2009 at 7:43 PM I'd replace the alternator, or take it to be tested fully.
Or jsut replace it with OEM, not pseudo- remanufactered ------------- 92 BMW 525iT Black on Black Posted By: javisam376 Date Posted: February 14, 2009 at 6:13 PM Just finished checking all the grounds... all of them throw 0.2 or 0.1 OHMS... is there another place i can use the voltimeter to try to track down the problem??? Posted By: javisam376 Date Posted: February 19, 2009 at 6:29 PM I measure the voltage at the amplifier and i got these numbers: Engine off / system down: 12.6V... thanks... Posted By: moparfan1234 Date Posted: February 19, 2009 at 7:08 PM it could just be the amp its self. i have had low class amps that just draw alot of power but dont put it out. barow a friends amp some then like a memphis JL kicker amp some then a lil better made. my diesel truck has stock a 140amp alt and 2 batterys. i had 4g wire to the amp and tryed alot of cheap amps and the lights would dim and they shouldnt for like a 500watt amp but the cheap ones will. i put in a 1000watt memphis amp the lights did not dim at all. if you know dodge diesels they have a grid heater that pulls over 200amps when its on and the lights hardly dim when thats on.
------------- 87 ramcharger eclipse CD5000 2 15" memphis M3 kenwood 900rms mono amps 99 dodge cummins diesel eclipse CD4000 1 12" memphis Mclass 800rms audiobuhn amp Posted By: bigchief2472000 Date Posted: February 19, 2009 at 7:09 PM did you charge the capacitor before installing it? im not sure if all caps need to be charged but all of my fosgate ones had to. that is strange to be dimming the lights with under 500 rms. i had a system in my old car that was running 800 rms with stock battery, stock alternator, and a 1 farad cadence cap and the lights would never dim on it even at high volume and bass boost all the way up.
Posted By: moparfan1234 Date Posted: February 19, 2009 at 7:16 PM my setup in my ramcharger has 2 900watt rms amps pushing 4 15" memphis M3 with stock 60 amp alt and a truck battery and my lights hardly dim thats with out a cap just 0 gauge wire ------------- 87 ramcharger eclipse CD5000 2 15" memphis M3 kenwood 900rms mono amps 99 dodge cummins diesel eclipse CD4000 1 12" memphis Mclass 800rms audiobuhn amp |
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