DiyMobileAudio.com Car Stereo Forum banner

1 - 14 of 14 Posts

·
Registered
Joined
·
60 Posts
Discussion Starter #1
I have been having problems with the lights dimming on my truck during heavy bass. It happens while at idle and while cruising.

My truck is a 2002 F150 with a factory 130amp alternator.

I have a Alpine PDX-F4(60amp) and PDX-M12(100amp) in the truck.

This is what I'm running:

1. "Big 3" with 1/0 Knu OFC
2. DieHard Platinum P2 - Sears: Online department store featuring appliances, tools, fitness equipment and more
3. Knu 1/0 OFC from battery to distribution block
4. Knu 4 gauge OFC to each amp
5. Ground distribution block, grounded with Knu 1/0 OFC
6. JL Audio ground lug, paint sanded away with Dremel on top and bottom of body.

I am not seeing much voltage drop. With the amps turned off it sits at 14.4V. With just the two amps playing loud and headlights on, the lowest drop I have seen is 13.8V.

I'm hoping a higher output alternator will stop my dimming issue. I found one that is rated for 105amps at idle and 250max. Would this be enough to stop my dimming issue? Even if it won't stop the dimming at idle, I'd really like to stop the strobe light effect while driving.

Thanks in advance for any help!
 

·
Registered
Joined
·
898 Posts
Dimming lights with that much voltage is 0_o.

For once someone has done the proper setup! I applaud you!

Yes a new alt will fix your issue. But is just weird to see that such a small drop has that much impact.
 

·
Registered
Joined
·
1,920 Posts
I have been having problems with the lights dimming on my truck during heavy bass. It happens while at idle and while cruising.

My truck is a 2002 F150 with a factory 130amp alternator.

I have a Alpine PDX-F4 ( 60amp ) and PDX-M12 ( 100 amp ) in the truck.
Indeed a HO Alternator is required for your system layout. The Sum Total of the 2 amplifiers fuses are the clue here ( 160 amps ).
 

·
Registered
Joined
·
898 Posts
Robert that is false. They will never come close to that.
 

·
Registered
Joined
·
60 Posts
Discussion Starter #5 (Edited)
Dimming lights with that much voltage is 0_o.

For once someone has done the proper setup! I applaud you!

Yes a new alt will fix your issue. But is just weird to see that such a small drop has that much impact.
You were correct. I had a chance to stop by my parents house today and test my voltage again with my dads nice Fluke DMM.

I was seeing as low as 12.5V on sine waves and 13.0V on bass heavy music.

I guess my cheap ass DMM isn't good enough to keep up with the actual voltage because of how quickly it moves.
 

·
Registered
Joined
·
898 Posts
TIME FOR A NEW ALT~

This will fix all your issues and you tested it with a proper meter. Nothing left to do but get that new alt! GOGO! :cool:
 

·
Banned
Joined
·
2,276 Posts
You shouldnt need one.. I think you need to check your grounds again and check your gain setting. Soon as the amp clips voltage drops will quickly increase.
 

·
Registered
Joined
·
60 Posts
Discussion Starter #10
You shouldnt need one.. I think you need to check your grounds again and check your gain setting. Soon as the amp clips voltage drops will quickly increase.
The gains should be set properly, but I will look into that tomorrow.

Also I tried grounding the amps directly to the frame and it didn't make a difference.
 

·
Registered
Joined
·
156 Posts
Fairly easy to test out the need for an upgraded alternator. Just pull up another car next to yours and jumper the electrical systems with some nice, heavy gauge cables. With the cars running, of course, see if the added electrical system improves your performance.

I haven't had anything but mostly negative experiences when upgrading (or trying to upgrade) alternators. Good luck.
 

·
Registered
Joined
·
10 Posts
>>160 amps max draw
>>possibly 100 amps available
No, you don't need a HO alt, but you could get a custom bracket made and add another alt of the same kind you already have from a junkyard/craigslist/ebay/so forth. 260a for another $150-$200 versus 280-300a for $500-$600 is a better way to go.
 

·
Registered
Joined
·
12,054 Posts
dont forget that the car need power too ;) if it has a 100A alt, then the car will pull 60-70 amps too.

so a higher output alt will help for sure.
 
1 - 14 of 14 Posts
Top