Ignition noise

[usraptr]

Did a search but didn't find anything on this. I have a 2002 Tige 22i with stock Clarion stereo, sub-woofer and speakers. The dealer added two tower speakers and an additional amp.
Worked great for several years and still does with the engine off. However, with the engine running I get an ignition whine that increases with RPM. Checked and cleaned all the battery connections and the ground connection on neg battery cable at the back of the engine block. That didn't make any difference. I installed a "noise filter" I purchased from Best Buy but that severely limited the sound coming from the tower speakers and strangely added a different static to the tower speakers like a blown speaker so I removed it. Nothing has been added/deleted or changed in the system since I purchased the boat new.
Any suggestions on what to check next?
Thanks in advance.

[chpthril]

Does you boat have one or two batteries? So this is not a new addition to the stereo, but the noise has recently started, right? Any other electrical type repairs done recently or accessories added?

[usraptr]

Two batteries with a battery switch. Came like that from the dealer. No electrical repairs or accessories added. Just started after being taken out of winter storage for the spring/summer. BTW, the boat is stored indoors in a heated garage.

[philwsailz]

I suspect a rat... Actually, maybe a mouse?

Sounds like the ground plane hasd been compromised somehow. Did you disconect batteries for winter layup?

Phil
Kicker

[usraptr]

Ignition noise

No they were not disconnected. They were hooked up to battery tenders. What about the battery switch. Would a loose or dirty connection there cause the problem?

[philwsailz]

Batt switch would not cause the issue you describe.

Noise as you describe comes from one or more of the audio components being on a different ground plane. This can often happen if the stereo components are not all sharing the same grounding point. A wire could be disconnected, a mouse might have chewed throgh a ground wire, dirty ground wire connection... these are all possibilites.

The thing to do on paper is going to be to trace all grounds first and make sure that they are connected properly. That sounds good on paper, but you are talking about digging and slowly pulling one wire at a time in a stock loom chasing it from here to there.

It will be usually easier and quicker to make the stereo mod we usually recommend. Specifically, now might be a good time to pull ALL of your power leads from your head unit, and any EQ's, signal processors etc and simply move them on new wire right to the power terminals of your biggest amplifier. Take the head unit ground and re-route it to the negative terminal of the big battery. Take the YELLOW head unit power wire and re-route it straight to the big amp's positive terminal. Then I prefer to take the head unit's RED power wire and run it thorugh a switch, (can be a dash rocker swicth, a relay energized by the accessory key switch, etc) and than after the switch take the red wire straight to the big power amp's positive terminal. NOTE: YOU WANT TO FUSE the yellow and red wires with probably a 5A fuse right next to the big amp so the fuses will pop in the event of a short circuit. This will prevent you from burning the boat down.

Do this for the head unit and do it for any EQ or signal processor you might also have in the stereo. 95 - 99 percent of the time this simple re-wire mod will take care of stereo noise issues, and it can usually be done in under an hour, usually about 30 minutes...

Let us know what you think...

Phil
Kicker

[usraptr]

Ignition noise

Thanks Phil. It may be a 30 minute job for you, but it will probably take me several hours. Anyway, I'll give it a try when I get a chance.

Re the batteries, both of mine are the same size, deep cycle marine cranking batteries. I have been in the habit of switching the battery selector between the two batteries, mid-trip, so that both batteries get charged. Is that necessary? Even though the battery selector switch is on the "cranking" battery is the "house" battery being charged at the same time and visa verse?

[philwsailz]

Unless you have an isolator or Voltage Sensing Relay, no, the only battery being charged is the one the batt switch is selecting. You switch your batt switch while running? Have you ever run the switch past OFF while the engine was running? If so, was it about the time you started noticing the noise?

Phil
Kicker

[chpthril]

You guys may be on to something. Not all battery switches are make-before-break, so its possible that the alternators voltage regulator has been damaged due to running open field.

[usraptr]

Phil, to the best of my knowledge I haven't switched batteries with the engine running or turned it past Off. The volt meter on the dash shows that the alternator is charging correctly.

[usraptr]

Not quite sure what you mean by "open field"?

[philwsailz]

Not quite sure what you mean by "open field"?

There is a "field coil" that is part of the alternator. That is what CHP is talking about.

Your charging system wants to be hooked to a battery. When the engine is running the alternator "sees" the battery load and provides current based on the battery's state of charge.
With a battery switch, at least some battery switches, it is possible to switch through the OFF position while changing battiers. If the motor is running, the OFF position removes all load and the alternator's field coil reacts badly with a big voltage spike, often blowing the voltage regulator and the diode-based bridge rectifier.

The rectifier converts the AC output from the alternator to DC. If the rectivfier is blown it will cause AC power to be present on the +12v power wiring.

Long story short, if the motor were running and the batt switch was run through the OFF position, you could have bllown your voltage regulator ad rectifier. This would put AC on your +12v power wiring, and that would cause the moto noise/whine. It would vary with engine RPM.

I'm not saying for sure this is the cause, just trouble-shooting. BUT if you do the power re-wiring mod as shared aboove and the stereo still whines, I would be looking at the voltage regulator....

What is indicated at your gage as your charging voltage?


Phil
Kicker

[SimonWS]

One of the most common things that will cause this is a cell that is failing in the battery. This is a very common thing to happen coming out of winter. I know in Texas, March and April are big months for battery replacements. If you still haven't found the issue or resolved it, then I recommend getting a battery tester which will tell you if there is a bad battery. Using a volt meter alone will not tell you if there is a cell that has failed or failing, all of the time.