wtf? alt whine

loudwagon15s · Post by **loudwagon15s** » Fri Nov 07, 2008 4:56 pm

I'm somehow getting alt whine like crazy, and how it happened is kinda complicated so here goes,

I have a jbl 4 channel front channel up to my comps, rear up to the sub. I miss being loud, so i bridged each channel onto each coil of the sub (dual 4) and a kid i met at college gave me a shitty legacy 2 channel for helping him install an alt that i was going to hook up to my comps. With everything off, i hooked up power, remote, and ground to the legacy (everything still hooked up on 4 channel) When i put the fuse in on the legacy, i noticed that the sub started to pulse like crazy

even though the only connection between the sub and the legacy was the remote wire, pos & neg (off of a distro block) I unhooked the legacy, and went back to my old setup, and when i did i got terrible alt whine while the engine was running (no wires were moved) If i hook up the rca's one at a time, the two that were hooked up to the jbl (front and sub) cause alt whine, however the pair not hooked up (rear) caused no alt whine, and a combination of the rear rca and anything else causes the alt whine to stop. (oh, no alt whine while car is off, or rca's unplugged, or rear rca's) So now i have no idea how to fix this, i've heard of peoples grounds going out on their rca's but dont know how to fix the problem.

MobileAudio219 · Post by **MobileAudio219** » Fri Nov 07, 2008 5:19 pm

I'd start with checking all your grounds, you probably got one loose somewhere... :)

If everything is good there, replace the rca cable thats making the noise...

loudwagon15s · Post by **loudwagon15s** » Fri Nov 07, 2008 6:29 pm

i dont think i have bad rca's or loose grounds, i just went through all my wireing when i was having voltage drops, i think somethin is f'd up with my hu

William from NOLA · Post by **William from NOLA** » Fri Nov 07, 2008 6:59 pm

You have your groundwire connected to bare metal right? No paint at all?

MobileAudio219 · Post by **MobileAudio219** » Fri Nov 07, 2008 8:05 pm

loudwagon15s wrote:i dont think i have bad rca's or loose grounds, i just went through all my wireing when i was having voltage drops, i think somethin is f'd up with my hu

Recheck them...

pull youre headunit and put the rear rcas to the front, if it stops than that tells you it's probably a bad rca...

I'm still thinking its a ground issue...

Bwcad1 · Post by **Bwcad1** » Fri Nov 07, 2008 8:10 pm

It's deffinatly a ground issue. Here is the kicker, this just happend to me with a AB1000D the internal ground was shot in the amp. Good luck. lots of times this happends if the amp is loose and moves around a lot.

loudwagon15s · Post by **loudwagon15s** » Fri Nov 07, 2008 8:22 pm

humm, hopefully its not the amp, but then why would the rear channel rca's cause no whine while the sub and front did (the ones that were hooked up at the time)?

loudwagon15s · Post by **loudwagon15s** » Sat Nov 08, 2008 9:29 pm

so i guess i'm asking, how do i ground the rca's on my deck?

swimmerdude · Post by **swimmerdude** » Sun Nov 09, 2008 9:02 am

the outer shields on rca's are the ground and the probe is the positive. attach wire onto the shields when you plug in the rca's and ground that wire out to some bare metal.

Bwcad1 · Post by **Bwcad1** » Sun Nov 09, 2008 9:17 am

This can cause your amp to die. your mixing AC and DC electricity, its good for a quick test but do not permanently leave it connected. If the noise stops you know its a ground loop.