ZCar Forum banner
Status
Not open for further replies.
1 - 13 of 13 Posts

· Registered
Joined
·
820 Posts
Discussion Starter · #1 ·
i have a nice stereo system. it is all grounded properly, but i still hear all the engine whining and turn signals, etc. it is very annoying. i tried trouble shooting this problem, i cant figure it out.

i to the fusible link box and unhooked a wire that went from the box to the positive battery terminal. is this stock? when i unhooked the wire, the radio worked, but the car was actually dead. i didnt have any headlights, rear lights, inside lights, and the car would not crank. what the **** is going on here? is there a way to hook up some kind of noise suppressor to each of the power leads in my system?

i have 3 power leads:
one amp for the woofer
one amp for highs and mids
one for the head unit.

anybody who helps me, thanks in advance.


david karey
socalz prez
 

· Registered
Joined
·
225 Posts
Same problem here..

I also have a high end stere system and can't figure out what is causing the road noise (whine) I know that it is not being caused by a part of my system b/c I have had it in another car with no noise at all so this must be some where in the car's wiring, I am not sure but it could be a bad radio condenser the little silver thing on your coil bracket.
Just a thought
-J-
 

· Registered
Joined
·
820 Posts
Discussion Starter · #3 ·
Re: Same problem here..

yeah it didnt make noise before i added the amps to the system. i have the amps hooked directly up to the battery. when i disconnect that fusible link wire from the battery, the car is dead but still runs the radio and i dont get any noise at all. go to your car and disconnect that wire and you will know what im talking about. are you able to hear your turn signals clicking in the speakers too? **** my 280zx is killing me also! so is there a way to get rid of this annoying problem?

david karey
 

· Registered
Joined
·
825 Posts
Re: Same problem here..

This may sound stupid to some people, including me, but I've found that sometimes if the grounds from the amps are too close to each other, or even connected, that it causes some sort of ground loop and causes a lot of road noise. I've had it happen a few times... grounded each amp to opposite sides of the car and it fixed it. It still doesn't make a lot of sense to me, but facts are facts!
 

· Registered
Joined
·
820 Posts
Discussion Starter · #5 ·
Re: Same problem here..

would it happen if i ground the amps to the same peice of metal? my amps are at different sides of the car but they are grounded to the same peice of metal. they are grounded to the storage compartment panel behind the seats in a 79 coupe.

david karey
 

· Registered
Joined
·
497 Posts
Re: Same problem here..

I've had this problem in the past as well and there are a few things you can do to help with the noise.

1. Make sure RCA cables are as least 18" apart from the power cables to the amps. If you need to cross them do it at a 90 deg. angle.

2. Different plug wires.

3. Different coil.

4. Grounds not grounded enough. If you have large power draining amps make sure you have a extremely clean ground connection.

5. A head unit with more preamp voltage is less suseptable to interferance. Mine has 4 volt preamp.

For reference, I am running a US Amp 1000x which is 1000 watts on two channels to 2 12" subs. and 100 watts by two to 2 6x9's and 100 watts by two to 2 1" tweeters.

Aren Shank
'78 280z Modified
Bend Area Datsun Association
http://www.bendareadatsuns.com/
 

· Registered
Joined
·
5,829 Posts
I have also the same problem with my car. if you shut the car off it will stop so that leads you to believe it is ignition or the alternator. My car is getting the noise from the alterantor. if you disconnect the plug in connector on the back of the alternator and start the car you will find, in most cases the noise goes away.
I gor the problem when I hooked up my amp also. The first setup was my kenwood deck and the amp, I was able to disconnect the ground side of the rca inputs to the amp and that cleared up the problem. Now I have a fosgate power 300 amp also and I have not been able to get the noise to go away. I was able to minimize the noise with a high current schotty diode from the main power to the battery, but not totally get rid of the noise. You will just have to play around with it to find what works for your system.

On another note, you described what made the noise go away by disconnecting the fuse link (the black link I believe) that indicates you have the amps hooked to the battery terminal. The problem with this connection on the car is that under high current loads you will burn up your connectors for the black fuse link over time, as all of the current the amps are drawing is going through the link from the alternator. I did this with my fuse links and got to looking at the schematic of how the car is wired and found the alternator wire(white wire) was connected through the black fuse link and when I was taxing the system for current to run the amps I was drawing to much current for the link, and the wire got hard, and the connectors, spade lugs, burned up over time.
What you will need to do is to run at least a #6 wire from the alternator to the starter plus wire to the battery, that way you will provide the battery with the extra current it needs from the alternator directly to the battery and bypass the black fuse link, and the rest of the car will continue to operate through the fuse links like Nissan designed them to do.
Let me know if you find a solution forthe noise. I have installed filters on the power to the amps, filters on the line level inputs to the fosgate and neither of those parts have corrected the noise problem. I have not tried the big 1 farad filter on the power cables, but I dont think that will help anyway. The line level inputs are the key to the noise problem, so if you try something work in the line level input area to fix the problem. You need to somehow isolate the grounds of the line input to the amp and that will fix the problem, but so far all the crap that you can buy doesn't seem to work and is a waste of money, at least it was for me, but you never know, different designers configure the front end of their amps differently and you just may get lucky with your setup.
 

· Registered
Joined
·
825 Posts
I don't know what that compartment looks like in a 79... my 74 has two compartments. I'm in no way knocking these guys ideas, I only know the ground thing from experience. I'd just try to get the grounds as far away from each other as you can. Setting up two amps can get kinda tricky! I'm not positive this will work for you, but at this point it seems like it's worth a shot, and it's simple enough, you know?
 

· Registered
Joined
·
107,597 Posts
make sure your ground leads are less than 12''. if not, as short as possible. don't have to be real far apart, just use a separate bolt for each ground lead. scrape the paint away from under the bolt you will use for the ground. usually, grounds are the cause of all whine and electrical noise in a system. he was right on when he said keep the rca's far away from the power and ground wires. but usually, it's the ground.
 

· Registered
Joined
·
2,280 Posts
Re: Same problem here..

Do you have your positive wires for your amps going to the same fusable link or distrubution box. If so, run seperate lines from the Battery to each amp, with a independant fusable link. Also do not ground both amps in the same place. Good luck
 

· Registered
Joined
·
1,351 Posts
guys, there is a component called a "radio condenser" mounted right beside the coil on my '78 stock. The purpose of this little capacitor is to eliminate interference with the radio...

If your car is missing this device perhaps you could ask a stereo expert to put one in, and show him your manual with one in it. He will probably understand your problem.
 

· Registered
Joined
·
130 Posts
I did custom stereo professionally for several years, and still "moonlight". All of these posts have great ideas. The ignition system should be cleaned up first. Take amp power directly from the pos of the battery and keep the grounds short. Run the signal (RCAs) and the power down opposite sides of the car. I put the power on the battery side and signal on the opposite in all installs. If there are still problems try moving the amp grounds. I have a Fosgate Punch 160,and a 400A4 in my 78 with no engine noise problems. One project that is at the top of my list is to replace the fusible links with either maxi fuses and upgrade the alternator.

Cliff
 
1 - 13 of 13 Posts
Status
Not open for further replies.
Top