PCA Forums

So my wife's 4Runner FINALLY had its cracked dashboard replaced. Now, I don't normally drive her car and I really wasn't paying attention to the radio before they touched it (they had to pull and disconnect the radio, Pioneer AVIC 910BT). Now, I hear a constant whizzing/noise regardless of which input it' set to (FM, SD Card, Aux, etc...) But, it only happens when the engine is on. Toyota had their after market radio installers check out the grounding and they said they didn't find any ground shorts, so they indicated either a speaker or the amp. But, when the engine is off, it sounds fine so I don't see how it could be the amp. I tried researching it and it looks like possibly some engine noise. I also read that issues with the battery could cause the noise. My battery was tested and told it was still good, but I know I've had a couple issues where the car wouldn't start and I had to get it jumped.

Just attach a wire from the negative to the chassis somewhere. Does the whine go up and down with RPM of the engine? I had that in my car and just stuck a wire from the ground to the ring on the RCA cables going back to the amp and that silenced it.

http://www.bcae1.com/images/rca/tempora ... html#demo4

I just stuck the wire in the plug when i plugged it in and its been held in by friction for 6 years now. Also I did not use fuses and just used a tiny wire.

Does the whizzing sound increase and decrease when the engine is reved?

Pugsley wrote:Just attach a wire from the negative to the chassis somewhere. Does the whine go up and down with RPM of the engine? I had that in my car and just stuck a wire from the ground to the ring on the RCA cables going back to the amp and that silenced it.

The Toyota dealer had their after market radio company take a look, I specifically asked them to make sure its grounded correctly and there isn't a ground short. They said they checked and it was all connected correctly, but I'm taking their word for it as if there was something for them to fix, I'd assume they would so they would get paid more from the dealer. Then again they said it could be the radio or the amp, so I question their abilities since it doesn't do it when the engine is off. I'm trying to avoid taking it apart. It's a bit of a PITA to get it all lined up correctly.

Executioner wrote:Does the whizzing sound increase and decrease when the engine is reved?

Yes it does.

I don't know a whole lot about Toyota radios but if it's like many made in the last 10 to 15 years, an aftermarket radio would require an adapter in order to work with the factory amplifier. Some of these adapters are simply harnesses that you splice the aftermarket radio into and plug them in. Other adapters work with the canbus so your steering wheel controls work.

Go to crutchfield.com, plug in your vehicle and options, and see what you would need to install an aftermarket radio so you know what you're dealing with. If you have an adapter that communicates with the canbus, it could be the problem.

Since it's a hum that changes with the engine, it's hopefully a loose wire. Some cars need a noise filter on the power feed into the head unit and/or amp.

Crutchfield's Noise Supression Guide: https://www.crutchfield.com/S-AtTJDvcVm ... guide.html

I've got a local installer that I trust and I've used in the past. I'm going to have them take a look ($95) and see what's causing it. If it is indeed something the Toyota dealer messed up, then I was assured by my service rep that he'll get it taken care of.

I can tell you there's a lot of reasons for this. The whine is produced by the alternator. Radios have to be installed properly to reduce it. Poor grounding is one possibility.

If you have an amplifier, poor shielding between the radio and the amp (if it uses shielded wires) carrying line level signals is another.

It's also possible that there used to be a choke on the radio and/or amp power line that wasn't reconnected.

Yeah, letting a pro audio guy look at it is your best bet.

I agree with FP - it's the alternator or voltage regulator.

ok, well I took it to my trusted installer today and they were able to find the issue. This radio was installed about 6-7 years ago and I guess they didn't have the simpler harness kits that they have now, so it was connected through the RCA outputs. Well, the RCA connectors weren't plugged completely in and the RCA shields weren't grounded. Once they fixed that the issue went away. They also moved the GPS antenna which was either put back in a crappy spot or it was never where it should have been. The original installer sucked and messed up a bit of the dash and some other crap, but thankfully the dash cracked anyways and Toyota replaced it.

What an ordeal all cause of this crappy dashboard that Toyota used (and other manufacturers too) back in the mid 2000s. Lets see, I spent 6 hours at the dealer for the dashboard, then another hour or so with them finishing the next day cause a speaker grill got cracked. Then another hour troubleshooting the noise a few days later, and now 3 hrs getting fixed finally. I had them clean up the install a bit and move an aux port. Thankfully there's wifi and I was able to keep on working on my laptop, but still, all that driving around sucked.

Doh, I didn't get a chance to contribute. I'll admit though, there's about 15 things that can cause engine noise, so a pro is the best way after the simple checks.