Sound fluctuation after Aerial replacement

Question

I have replaced the Aerial on my car because the original one broke (car wash), the factory replacement is quite expensive, so I replaced it with a cheaper one.

The stereo itself seems to work fine, the CD player works, AM radio stations also work without any issues.

The problem is with the FM stations. The stereo can have normal sound output, but often gets quiet, sometimes goes mute when trying to listen to FM stations. This happens to all the stations at the same rate at the same time, so I'm struggling to believe its just a reception thing. The change in sound levels seems to be mostly random, the car can be sitting still and the sound levels will still change.

This happens more often than not. I have read a lot about needing a good ground for the aerial to work, and wonder if this is part or all of the issue. I tried to ground it better, didn't make any difference, but might not have grounded properly either.

Thank you for any ideas.

VEHICLE SPECIFICATIONS

2001 Holden Commodore VX Berlina Series 1

Stock Stereo (Eurovox, don't have the model)

IMAGES

Answer 1

The quieting and muting you experience might be static suppression that some car radios have, which means that sometimes you are getting poor reception at that moment. Try driving into an underground parking and see if the radio goes quiet. If it actually is noise suppression then the new antenna is clearly doing a poor job, do check the contacts just in case. Electrical contact cleaner should come in handy.

Answer 2

I tried a replacement antenna (aerial?) once, the antenna itself was great, but it had a defect in the base that attaches to the fender. The connection from the antenna attachment point to the wire inside was bad & would cut in & out. Testing it with a multimeter from the outside antenna (or outside attachment point, since your antenna's not bare metal) to the inside wire, and wiggling the wire around confirmed that it connected & disconnected. A break anywhere in the wire would do the same thing.

I'd try another replacement, they one you've got might be bad.

And if your original antenna had a ground cable, but the replacement does not, that won't help things. I think most of the cheap replacements rely on them touching metal on the inside of the fender as a ground, and your fender probably has paint or some coating on the inside to prevent rust, that also prevents a good ground. Sanding a small area where the replacement antenna touches the inside of the fender might help, but I could see it leading to possible future rust too. You could try & attach a wire from the original cable's ground point to the new antenna somewhere, a small hole drilled somewhere safe onto the inside "clamp" perhaps.

Or, a local junkyard might have a used antenna from your same model car (or any Holden, companies use the same parts on different models sometimes) for relatively cheap. Then you'd get all the required factory connections.