[Mk2] [Generic] Getting rid of power steering whine

[toxo]

My ice has been in various states of repair recently what with me having to remove it all to have the car worked on and then having an amp blow up but it more or less consists of this:

Panasonic double din tape / cd head unit with a single pair of preouts (this is temporary)
Preouts split (not ideal I know) and 2 sets of RCA cables run through to the frunk
A 2 farad power cap, distribution block, and the following 2 amps, mounted on a board in the frunk:
Directed Audio Viper 1200.1 running in bridge mode
Soundstream Rubicon 102 running in stereo mode with a high pass filter set at 150Hz

In the car I then have a set of Alpine dddrive components in the doors, w/passive crossovers also in the doors, and 2 10" Vibe subs behind the seats in some neil_turbo boxes. The subs are attached to the Viper amp in parallel.

It works really well, and sounds really very nice. Everything's crisp and clear, all ranges of sound are reproduced well (for a car install anyway). Because my car is a GT-S it wouldn't have had the premium sound system (it had a broken head unit when I got it) but it sounds a lot nicer than cars that I have been in that do have the premium kit. In the little storage pocket by my right knee I have a wired remote pot for the viper amp so I can turn the subs up / down depending on how the CD has been EQ'd to maintain a nice sound.

However I have been struggling to get rid of the dreaded power steering whine. It's present on all amplified speakers (you can even hear it from the subs very slightly, even though they shouldn't strictly be able to reproduce it) and wasn't present when the components were driven directly from the head unit. However its level is constant regardless of what the volume is set to on the head unit.

I have my RCA, speaker, remote turn on and viper remote control lead cables going through to the frunk via a grommet I found behind the instrument cluster (you can only just reach it with the i/c out) which comes out next to the brake master cylinder. They're then cable tied to the spare wheel holder to keep them away from the PAS motor. They're not run with the power cables for the amps, and wherever the two cross on the amp board I've crossed them at right angles so there shouldn't be any RF broadcast.

My next step is to take some pictures so you guys get a better idea of what I'm on about, and to try isolating the head unit by running it from a bench supply, to see if the noise is being introduced by the HU. This was an idea suggested by a friend of mine who rebuilds amps and PA equipment and it seems like a sensible one.

Does anyone have any other suggestions for things to try?

[ChrisW]

Did you get anywhere with this? I've just installed an amp and got the same problem. I can still hear the noise if I disconnect the RCA cable, so it must be getting picked up on the power cables or in the amp itself.

[toxo]

No I didn't In fact the whine got worse, and was joined by another one that went up and down with engine speed and then my alternator packed up. I have a new alt now but am about to remove all the ICE again so that I can go camping for a week. Another thought had crossed my mind though, which was putting a cap across the top of the power steering motor.

[Matt_Cooper]

For a start, get rid of the power cap. They do nothing, other than put strain on the electrical system and also give other losses due to possible bad connections.

Use a good quality 0 gauge cable and run it into a distribution block, then straight to the amps.

Also, the earths from the amps should go straight to a good earth. I.e. sand paint back to bare metal, use gold plated terminals and also 0 gauge cable.

You can also try earthing the head unit to a better place, other than the battery, which is where it will currently be earthing to.

Another thing to try is earthing the rca leads. Some leads come with a small wire running down the middle of them. If you earth this at both ends it can help eliminate interference.

Then as a last resort, run the power cables and signal wires down different routes so they are as far away as possile from each other.

[toxo]

Use a good quality 0 gauge cable and run it into a distribution block, then straight to the amps.

Am already using 4AWG welding cable (stranded copper) which should be plenty for the application.

Also, the earths from the amps should go straight to a good earth. I.e. sand paint back to bare metal, use gold plated terminals and also 0 gauge cable.

Already am, ish. They earth through the distribution block rather than directly to the chassis. One amp can only accept 4AWG cable and the other 8AWG, so that's what they're using (and it's good quality cable, not an eBay amp install kit). The distribution block then has a suitably good earth.

You can also try earthing the head unit to a better place, other than the battery, which is where it will currently be earthing to.

Right, directly earthing the HU is on my list of things to do (as well as providing a direct permanent +12v supply from the battery/distribution block rather than the one in the loom) but it won't currently be earthing directly to the battery. The loom wiring will earth to the chassis behind the dashboard (there are a few places it connects around the door hinges) rather than directly to the battery.

Another thing to try is earthing the rca leads. Some leads come with a small wire running down the middle of them. If you earth this at both ends it can help eliminate interference.

Mine don't have the small wire (which I've used to carry the amp turn-on signal in previous installs).

Then as a last resort, run the power cables and signal wires down different routes so they are as far away as possile from each other.

Already done

[Matt_Cooper]

Have you tried it without the power cap?

The next thing to do is uprate the big three.

Basically the main power leads on the car...

* Negative battery terminal to chassis
* Negative battery terminal to engine
* Main power from alt to battery

If you upgrade all these to 0 gauge cable you'll be onto a winner mate.

Its the first thing that should be considered wen you get any kind of voltage drop, or if your lights go dim on heavy bass lines. The power cap will also worsen this and unnessecarily zap power.

[toxo]

Yep, tried it with and without the cap, it makes no difference to the whine. One of the reasons I'm reluctant to ditch the cap is that it makes a noticeable difference to the performance of the Viper as that has very little in the way of capacitors inside it.

Unfortunately the battery to alternator (including fusible link) is about 6m long and an absolute xxxx to replace, and I'm not even convinced there is a direct earthing link battery -> engine. I'd also like to stress that I'm not having lack-of-power issues as you describe (I've had them before in a different car) there's no RPM changes or dipping headlights with heavy basslines etc. Just the whine from the steering motor...

[^Trickster^]

I just removed 2 300w amps, front speakers and sub behind passenger seat, my amps are under the passenger seat also.

I did a direct replacement keeping my existing audio wires, basically changed a new 12" sub into the box, replaced the amps with a 4 channel 600w and replaced the front speakers.

Now for no reason I have the power steering whine and a slight whine with the engine revs like yourself and its doing my nut right in!

Apart from that im no help at all

Graeme

[Peter C]

I've recently installed the following in my '2:

JVC CD/MP3 head unit - connected to original wiring via a Halfords plug.
Infinity Reference 6.5" mids and tweeters, with x-overs, fitted within the doors, powered by the head unit.
American Legacy 2 x 500watt amp in the frunk, + and - connected directly to the battery using suitable grade cables.
Amp bass level control knob in the sunglasses storage pocket.
Amp powers a pair of 10" Infinity subs, located behind the seats.

The install is 100% DIY (by me). I don't have any issues with PAS or alternator interference.

Toxo, you're not a million miles away from me. I would be happy to help if you want to meet up to test your installation using some of mine.

Peter C

[toxo]

Thanks for the info Peter, and the offer. I'm going to do some work to my install over the weekend to make it all easier to remove and I'll take the opportunity to renew earth points, check cabling connections and routing etc. I've recently had an alternator and now battery failure, and having replaced both of those in quick succession the whine only appears to be coming from the subs, which suggests it's only the Viper amp that's at fault...

[Peter C]

Cool.

Good luck and keep us posted.

The offer is there if you need help.