AC Compressor Noise through Speakers

[Quinn]

I recently installed a new amplifier and radio head unit. The install seems to be successful, except for one problem. I get a popping noise through the speakers everytime the AC compressor clutch kicks on/off. Other than that, there is no other noise. I don't seem to be getting noise/hum from any of the other usual suspects such as alternator, blower, fans, etc. I do have an unusually long ground wire running from the frunk (where the amplifier is mounted) to the battery. So maybe that's the issue. Are there any other better/closer grounding locations I could try? Any other ideas how to suppress the compressor noise? The head unit is grounded with the same wire as the old radio.

63350

[dn010]

You might try this to fix the issue.


http://dmctalk.org/showthread.php?12203-Electrical-noise-fix-for-AC-compressor-clutch

[ritztoys]

You might try this to fix the issue.


http://dmctalk.org/showthread.php?12203-Electrical-noise-fix-for-AC-compressor-clutch

I can attest that this method works, I kept frying my console clock because of this spike, now no more issues.

[Quinn]

Thanks for the tip. I will give it a shot and report back.

[CriticalB]

I used to have engine whine and the same popping issue when the compressor clicked on. I added a ground loop isolator (https://www.amazon.com/PAC-SNI-1-Noise-Isolator/dp/B000K50HJE/ref=sr_1_6?crid=3ID7V3YOQLIJI&dchild=1&keywords=ground+loop+isolator&qid=1587396503&sprefix=ground+loop%2Caps%2C186&sr=8-6) that solved both problems.

[dn010]

I am pretty sure I had to buy the zener diode in bulk. If you want me to send you one let me know and I'll mail it to you, I will just have to find them!

[Quinn]

I am pretty sure I had to buy the zener diode in bulk. If you want me to send you one let me know and I'll mail it to you, I will just have to find them!

Thanks for the offer, but I ordered some on Amazon after reading your suggestion yesterday. It was $3 for 20, so no big deal. Of course with all the coronavirus shenanigans, the arrival date is anywhere from May 8 - June 1. :shock:

[Quinn]

I just wanted to update this thread, in case someone does a search for this in the future. The problem has been resolved. I installed a diode on the AC compressor with only marginal results. It did reduce the volume of the popping noise, but it was still there. Following some additional advice from Dave, I ran a dedicated ground back to the battery for the stereo head unit. This solved the problem completely. Apparently, the stock radio grounding location on the faceplate, behind the console, is not ideal.