Thread: Stereo System Thumping = Lights Dimming?

Originally Posted by I800C0LLECT

How about add the proper grounds instead. It's a lot cheaper.

I had many grounding points..even the frame. Would still dim at idle. Even running just a JL 500w slash amp.

The draw or load at certain moments may be different, but many performance cars running multiple high output systems such as boost a pumps, msd dis4, sometimes 2+ intercooler pumps and other crap that draws a lot use stock alternators just fine. 10ga. wiring from the alternator to post, or your big 3 and then a volt booster, usually the s2 version or whatever.

There is also the idle tables for alternator output like below, if the number is below this the alternator is commanded off -
Accessories -> ALT -> Alternator RPM Cutout
File Location: C:\Documents and Settings\Administrator\Desktop\BINS\01_GTP_BIN_STO CK__original_.bin

RPM Trans Not Trans Enga
0 0 0
100 50 50
200 100 100
300 200 200
400 250 250
500 300 300
600 500 500
700 525 525
800 550 550
900 650 650
1000 750 700
1100 900 700
1200 950 725
1300 950 825
1400 1000 925
1500 1200 1100
1600 1300 1200
1700 1400 1300
1800 1500 1400
1900 1600 1500
2000 1700 1600



[TinyTunerData]
0,0
50,50
100,100
200,200
250,250
300,300
500,500
525,525
550,550
650,650
750,700
900,700
950,725
950,825
1000,925
1200,1100
1300,1200
1400,1300
1500,1400
1600,1500
1700,1600

Originally Posted by thegipper

I've been told that adding a HO alternator will NOT fix the problem. I also have this problem and was told by many that what I need to do is check the grounds on the car and clean them up. If it still dims, then you need to install a 10 gauge wire from the neg battery terminal to the chassis. Also add a 4 gauge wire from the neg battery terminal to the transmission case. This will help ground the battery better thus eliminating the dimming of the lights.

I haven't tried it yet but I will report back after it do it. I can assure you that adding a cap will NOT help as I already have a 2 farad capacitor and it still dims. I do NOT have a cheap amp either. I'm only running a 1k watt mono block to a single JL audio 10w3.

Hope this helps.

Thanks. Let me know the outcome. It's been bugging me for quite some time now.

Originally Posted by thegipper

install a 10 gauge wire from the neg battery terminal to the chassis. Also add a 4 gauge wire from the neg battery terminal to the transmission case.

Hope this helps.

10 gauge seems awful small to help. Im running 4 gauge from post to frame. Havent tried an additional ground from post because it doesnt seem necessary. Im pretty sure the HO alternator will solve it all, but I havent been able to get my hands on one. I was shown a site yesterday for one, but it said for years 97-02 and I will not purchase another thing for an 03 that says that, as everything the says 97-02 hasnt worked yet