Engine noise through RCA's ( NOT PIONEER)

[WashYourWinky 10+ year member]

I have engine noise through my RCA's. Sub amp only. The hu in question is a Alpine CDA-7894.

I have tried different RCA's, different ground locations for the hu including straight to the battery. Also grounded the antenna. I would try to ground the rca's but they are set up different than the Pioneer units, and I don't know how to ground this type.

Its not my amp the sound stops when I unplug the rca's.

I'm starting to think the hu is going bad.

I'm sure I have missed something, what do you guys think?

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[DBDRAGGUY 10+ year member]

Amp ground

 

[Kevinn 10+ year member]

Amp ground

Thats what I think too...

 

[Grinder1989 5,000+ posts]

Bad internal RCA ground in the headunit or the amp.

 

[WashYourWinky 10+ year member]

Bad internal RCA ground in the headunit or the amp.

Anyway to confirm either of those?

 

[Grinder1989 5,000+ posts]

If you have a multimeter, yes.

 

[WashYourWinky 10+ year member]

I forgot to add that I get noise through the sub when I change songs.

 

[WashYourWinky 10+ year member]

If you have a multimeter, yes.

I do have DMM.

 

[Grinder1989 5,000+ posts]

Set it to continuity.

Start with the amp and put one probe on the ground terminal and then touch the outer part of the RCA connectors with the RCA's unplugged. If it beeps then you're good. If not, then that's not good.

Do the same to the cd player. One probe on the chassis of the CD player and the other to the outer part of the rca connectors. If it doesn't beep, you'll have to get it fixed.

 

[WashYourWinky 10+ year member]

Set it to continuity.
Start with the amp and put one probe on the ground terminal and then touch the outer part of the RCA connectors with the RCA's unplugged. If it beeps then you're good. If not, then that's not good.

Do the same to the cd player. One probe on the chassis of the CD player and the other to the outer part of the rca connectors. If it doesn't beep, you'll have to get it fixed.

Awesome! Digging out the DMM right now.

 

[Grinder1989 5,000+ posts]

The grounds in the CD player are probably the cause. It could be the amp though. I had an amp in my truck that was doing that. It had a busted trace. I can fix the headunit or the amp if you need me to.

 

[xNaStYx 10+ year member]

I had the same problem. Then I changed the ground on my amp. Fixed everything

 

[WashYourWinky 10+ year member]

Okay, CD player checked out fine. The amp did not.

 

[WashYourWinky 10+ year member]

Its not the amp in my sig. The amp is a RF Power 800a2.

 

[Grinder1989 5,000+ posts]

Its not the amp in my sig. The amp is a RF Power 800a2.

I would be able to fix it for you if you're interested. You have bad RCA's.