• Welcome to the Contour Enthusiasts Group, the best resource for the Ford Contour and Mercury Mystique.

    You can register to join the community.

Headlights flicker with bass

7

79mustang351w

Hard-core CEG'er
Joined
Nov 13, 2010
Messages
1,254
Location
Bucyrus, OH
Ok...I got a brand new Optima red top battery and a brand new factory replacement alternator...so those are not it....and I have verified those with scan tools. My headlights stay constant without my subwoofer on. When I kick it on and start cranking it up...I notice the headlights somewhat flicker with the bass every now and again. I have a Pioneer 5200BT head unit , Memphis door speakers and 12" single sub, and a 400w Apline amp. Nothing serious...do I need a capacitor, bigger battery or amp power wires....whats up with this???
 
i used to have the same problem with all my other cars when i had systems in them. its usually from the amp draining the power from the battery when the bass hits. & it will pull power from the weakest source. when i had my s-10 ss i had 2 10in solo barics w/ a 800w kicker amp & when the bass would hit in that all my lights would dim just about all the way out. but when i got my 1st tour i went to 2 12'' square L7s & a 1200w kicker amp w/ a capacitor & it still did it, not as bad as the ss did so i ended up putting another battery in the trunk just for the amp & that helped out alot. nothing would dim out when i had that in there, cuz it wasnt running off the cars battery, i did run the battery off the alternator so it can recharge but i did have an upgraded alt. for it too. so with what you have i think you would be fine just getting a capacitor
IMAG0194.jpg
 
Yeah...cause its nothing big or serious....and everything else works fine on the car...just the dimming. Actually idk if its just in the system....cause last night...it was dimming and flickering slighty just at idle...with the sub turned off. So idk. These cars piss me off....so tempermental!!

I had a DB 220amp alternator in till the voltage reg. took a ••••. It had PLENTY for anything I would EVER throw at this car....but it whinned like a •••••....and I wish I would have bought their 200amp....didnt see that option when I bought the big boy at the time. Story of my life....
 
I find that my headlights will flicker a bit when coming to a stop and I have no system and more often than not I don't even have the radio on. Most days I just tell myself its a stronger case for and HID kit, less draw and the alt...too bad its 'illegal' to outfit HID in a non factory fashion. In another car when I was in highschool I had this problem with 400w Alpine and another battery did the trick, it just looks ugly sitting in the trunk.
 
A cap will work as a bandaid for the problem if thats the route you want to go. The real problem is the crappy little factory ground wires used on the car that need to be upgraded to larger aftermarket wire. Search for the "big three upgrade" for a how-to. It's very cheap/easy to do and very effective. Much cheaper than a cap.
 
LOVING car audio I have a decent amount of experience!
Sounds to me more like a connection but I could be wrong.
Our alts have more then enough amperage to power your system.
Make sure your amp and sub are wired correctly, check your stereo connections in back, check your voltage as you bump your stereo, with a good quality digital voltmeter.
If it drops when it hits a cap is needed, until you do the big 3.

I went to 0 Gauge and replaced all terminals that couldn't be properly cleaned. WHENEVER you do electrical make sure all wires are insulated and secured, if near heat(that can melt insulation) use a hefty wire loom. ALSO IIRC the fuel line is near the back of alt(even p/s which when hot is somewhat flammable)

Always disconnect batt - when working on the car electrical.
 
Ok...thats kinda what I wanted to hear. I was about ready to start making bigger and new ground and power wires like my Stang has. These stock ones looked to tiny to me. Thanks for your help...I will let you know what I figure out.

Any links to the big three threads??
 
Even my 340w RMS amp powering my two 12" subs (4g power wire) made headlights dim. I got HIDs and haven't looked back. HIDs don't dim. Ever.
 
I have 2 amps in my daily driver and I just set my idle speed to around 1,200 and it has plenty of juice. Problem is no output from alternator at lower rpm. A higher amperage alt wont help that, alternator overdrive will.
 
zorrex said:
Even my 340w RMS amp powering my two 12" subs (4g power wire) made headlights dim. I got HIDs and haven't looked back. HIDs don't dim. Ever.
Click to expand...
Because the ballasts act like a cap, its just a bandaid for the headlamps. The ground issue is still there.

2000ZxT said:
I have 2 amps in my daily driver and I just set my idle speed to around 1,200 and it has plenty of juice. Problem is no output from alternator at lower rpm. A higher amperage alt wont help that, alternator overdrive will.
Click to expand...
Or you could replace 3 simple wires and fix the problem. The Contour has a very good output alternator stock, more than you would ever need short of a competition stereo. Again, the problem is the factory wires, fix those and you won't have any dimming problems at any speed.
 
I have the big 3 and alt rewire ... my car dims like crazy at 750 idle with my stereo going. I used to be a car audio installer.
 
I run 1400-1500rms on 100% stock electrical (voltage drop to low 12/high 11- no budget to upgrade) and my headlights barely dim on music. Test tones are another story. Make sure you have secure grounds and a big 3 done with some quality grade wire and you shouldnt drop below 13v up to about 1400-1500wrms. Once you get above that, if you add another battery with high amp hours (at least 100) and you'll be good for up to 2000-2500 depending on if you street beat it or just do short burps for competitions. I have seen a Chevy Aveo run a 3krms monoblock with just 1 additional battery and a stock 90a alt at a comp. But that extra battery was fuggin huge.
 
Last edited:
I as well work in car audio..just like everyone is saying, the big three is huge. If you were to do an extra battery, in my opinion, a yellow top would be your best bet if you don't want to spend the extra for something along the lines of an xs power battery. You can find them on summit racing for about $200 and up. I personally did the big three and was running about 1000rms and there was still a little dimming and everything was done with 0ga wire. Hope this helped a little
 
I would check to make sure all the ground wires are secure are free of corrosion before doing anything . Its sounds like the problem is a grounding issue more than anything.

IMO the big three isn't that huge an issue on the Contour. The OEM ground wire are both fairly short, the gauge is more than sufficient considering their length. The alternator wire is the only wire long enough that replacing it with a larger gauge might make a difference.

If you have the time and tools it wouldn't hurt to do the big 3, but don't be surprised if it doesn't fix the flickering headlight problem.
 
I have a few other issues that may be the cuplrit....I will let you guys know. It may not have anything to do with the damn stereo setup...because it was working prime before some of these issues arrised.
 
You may be killing your battery. I killed 3 batteries (lead acid(in about 2 months)) with my sound system before I bought a $300 battery which has lasted me. The alternator has an amperage ramp depending on speed, if you change the pulley size you therefore change the speed at which is it at idle, make it rotate more at idle (smaller pulley) and you will therefore have more amperage available at the same speed. Say you are at 50% volume on 800 watt sound system leaving current headroom you could still be running up to 15-30 extra amps at idle.

I think the difference in experiences and opinion is how obnoxiously loud you listen to music in traffic (idle). I am pretty obnoxious...

This is not for our alt but a good example. Just food for thought.
10si%20perf%20curves_400.jpg
 
2000ZxT said:
I think the difference in experiences and opinion is how obnoxiously loud you listen to music in traffic (idle). I am pretty obnoxious...
Click to expand...


This. I dont go over 3/4 volume at traffic lights or I get mean looks and people put their windows up :D and my voltage drops terribly low. I can't wait till I can wall the trunk off :drool: , that is if the car lasts long enough for me to.
 
I have 4GA feeding sometimes 6 woofers, but mostly 4 and i ALWAYS get dimming lights. (not my headlights, HIDs don't dim) but my dash lights, or anything else on it dims bad. I know i could use larger wire but when i had only 2 woofers which were pretty low rms i still had dimming issues. My grounds are good, i am running an optima battery, and have a 10 farad cap. My cap has a volt readout and at an idle, it dips to about 11V and i haven't seen it while revving because of obvious neck breaking angles.
 
silver rocket said:
I have 4GA feeding sometimes 6 woofers, but mostly 4 and i ALWAYS get dimming lights. (not my headlights, HIDs don't dim) but my dash lights, or anything else on it dims bad. I know i could use larger wire but when i had only 2 woofers which were pretty low rms i still had dimming issues. My grounds are good, i am running an optima battery, and have a 10 farad cap. My cap has a volt readout and at an idle, it dips to about 11V and i haven't seen it while revving because of obvious neck breaking angles.
Click to expand...

When your voltage starts to dip below 12, its time to back off the volume. When you dip below 12v, your amp can clip and blow the woofers, even if the gains are set properly. Caps wont do much at all, they are a marketing scheme. Amount of woofers doesn't mean anything but if they are wired to a low ohm load itwill tax the hell out of your electrical system because of the increased current draw of the amp. Sounds like you need to add an extra battery, around 30-50ah or so- In between an XS Power 975 and a 5100. No more than $200 tops.
 
You must log in or register to reply here.
Back
Top