I bought two NEW rockford fosgate PRIME amps, one to power the subwoofer and other to power 6x9s. Car is 1995 BMW 325i engine that has 6 ignition coils. Head unit is new Pioneer connected to the stock wiring harness.
RCA cables are quality but they are not twisted kind and they run alone to the rear of the car. Remote is run from other side. Amp main power is in the trunk sense BMW has batteries in the trunk. all connections are clean and I use quality power cables.
There is no noise when RCA cables are not connected to the amps. Soon as I connect them I get ignition noise static even to speakers that head unit powers as well as speakers that amps power.
There is a whine that can be heard as well though but not nearly as prevalent. At 0 volume there is no noise. At 1 volume the hissing static shows up. As I increase the volume there is no change in the volume of this static noise, but when I rev the engine I can hear the whine change tone. The radio increases with the volume just fine though and at higher volumes I can't notice the static.
Where should I start checking? What do I need to do?
RCA cables are quality but they are not twisted kind and they run alone to the rear of the car. Remote is run from other side. Amp main power is in the trunk sense BMW has batteries in the trunk. all connections are clean and I use quality power cables.
There is no noise when RCA cables are not connected to the amps. Soon as I connect them I get ignition noise static even to speakers that head unit powers as well as speakers that amps power.
There is a whine that can be heard as well though but not nearly as prevalent. At 0 volume there is no noise. At 1 volume the hissing static shows up. As I increase the volume there is no change in the volume of this static noise, but when I rev the engine I can hear the whine change tone. The radio increases with the volume just fine though and at higher volumes I can't notice the static.
Where should I start checking? What do I need to do?
Perry Babin to the rescue, you are my hero and I told you that many times before.
I just removed the Pioneer CD deck from the dash and ran another RCA cables from the deck to autside the car into the trunk into the RF PRIME r250-1 amp and static noise to the speakers that deck controls is gone, nice clean sound. But I still get static into the woofer that r250-1 amp controls but less, when I turn the deck down to volume "0" I get the engine noise at the woofer, then when I disconnect the RCA cables from the amp the static is gone.
What would be my next step?
An externally hosted image should be here but it was not working when we last tested it.
I am not using the bass boost knob that comes with the amp. There is no static when I disconnect the RCA from the amp. When I connect the RCAs to the amp even if the deck is at zero volume I get static. This mean that noise is comming from RCA that I rerouted outside the car. I don't know what would be my next step?
Run separate power lines to the deck?
I pulled it out and held it in hand outside of the dash when I was testing. There is noise.
I searched google pioneer deck rca noise and found out this:
An externally hosted image should be here but it was not working when we last tested it.
That's generally the cause of engine noise and it doesn't stop when the volume is set to 0.
RCA Shield Repair
RCA Shield Repair
Hi hakentt.
Do you have negative and positive wires staright from your battry to the amplifier or have you just positive cable and connected negative to the body work. If you have connected positive and negative directly to you batrrey then remove the amplifier negative from the battrey and attach it to the body work instead. Make sure you connect the negative to the chassis at the side furthest away from the battery. I have seen this problem many times before and it will misslead you into thinking the noise is comming down the RCA's
Best Regards Ian
Do you have negative and positive wires staright from your battry to the amplifier or have you just positive cable and connected negative to the body work. If you have connected positive and negative directly to you batrrey then remove the amplifier negative from the battrey and attach it to the body work instead. Make sure you connect the negative to the chassis at the side furthest away from the battery. I have seen this problem many times before and it will misslead you into thinking the noise is comming down the RCA's
Best Regards Ian
Last edited:
Hi perry . The op says the head unit is brand new.What do you think would make F531 go open circuit. Do you know what rating F351 is. There are a couple of reasons why this fuse could open. 1 the power ground to the head unit is faulty causing negative to route through the ground connection of the RCA this depending on the fuse being a low amperage one. 2 The op has inadvertantly shorted the RCA ground to positive in some way.
Last edited:
#2 virtually every time. It takes only a fraction of a second to open the fuse. It generally happens in the back of the vehicle when the RCA shields contact the power cable.
Below is a section of the board layout. You can see the fuse in-between the RCA shields and the amp case ground.
Below is a section of the board layout. You can see the fuse in-between the RCA shields and the amp case ground.
Attachments
I took the deck appart right now, to get to the fuse whole unit needs to come appart. Deck is new but I had it stored for 5 years, it is posible that I touched with one of th RCA cables positive post yesterday when I was trying some old junk coustic amps.
At the fuse location I see component with letter 'c' on it, asuming this is the fuse and should have connectivity accross but it does not?
yes I got both leads connected directly to the amp because battery is right there. I will try moving the ground cable, I don't see why it would make a difference.
At the fuse location I see component with letter 'c' on it, asuming this is the fuse and should have connectivity accross but it does not?
An externally hosted image should be here but it was not working when we last tested it.
yes I got both leads connected directly to the amp because battery is right there. I will try moving the ground cable, I don't see why it would make a difference.
Hi Hakentt.
Yes that is the correct fuse. The first time i found out about having the negative lead to the battry i couldnt belive it myself. negative is negative after all is what i was thinking , surley connecting to the battry with two nice thick cables would be better Than one copper cable and a piece of steel well i can assure you it didnt work like that i had created a massive ground loop . The only diffrence with your install to the ones i came across is that your battry is in the trunk so there is a good chance you may get away with it . If you do still get a little noise after you have sorted the fuse . Then instead of removing the negative lead fron the battry a smaller piece connected at the amplifier along with the big cable and the other end to the chassis worked in a lot of case too. I think once the fuses is replaced all will be well Thanks to perry. As perry says this type of thing happens lots so i guess that is why the manufacturer fitted a fuse in that location . Apart from saftey issues it will also alow them to tell that someone had shorted the rca's to positive or maybe speaker out and would be able to charge the customer for repair all quite fair as it would be a customer generated fault..
Seasons greetings to both you and perry .
Regards Ian
Yes that is the correct fuse. The first time i found out about having the negative lead to the battry i couldnt belive it myself. negative is negative after all is what i was thinking , surley connecting to the battry with two nice thick cables would be better Than one copper cable and a piece of steel well i can assure you it didnt work like that i had created a massive ground loop . The only diffrence with your install to the ones i came across is that your battry is in the trunk so there is a good chance you may get away with it . If you do still get a little noise after you have sorted the fuse . Then instead of removing the negative lead fron the battry a smaller piece connected at the amplifier along with the big cable and the other end to the chassis worked in a lot of case too. I think once the fuses is replaced all will be well Thanks to perry. As perry says this type of thing happens lots so i guess that is why the manufacturer fitted a fuse in that location . Apart from saftey issues it will also alow them to tell that someone had shorted the rca's to positive or maybe speaker out and would be able to charge the customer for repair all quite fair as it would be a customer generated fault..
Seasons greetings to both you and perry .
Regards Ian
Thank yourself. It may have been quite a few posts before I would have suggested testing the shields... unless you would have stated that it was a Pioneer radio in the early posts. I've never heard of the open shields causing hissing or having the noise stop when the head unit muted. Generally the complaint is extremely loud engine noise.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.