Speaker Crackle

[Oneball]

I'm getting a crackle from my speakers, Becker Mexico CC with Auditorium.

It occurs when relays turn on and off eg heater, wipers.

It can also occur randomly without any noticeable cause.

It will happen with the radio on or off, the ignition on or off and the engine running or not.

The radio obviously has both a permanent and switched live as it'll work with the ignition off but will also power down when the ignition is switched off.

The radio wasn't working when Richard got the car due to the fuse in the amp being blown, he replaced it and it worked.

I've got a more modern radio coming anyway but just wondered if anyone had any thoughts.

Thanks Tim

 

[Oneball]

I've ruled out the head unit as I still get the noise with it removed from the car, so it's either the amp or something in the wiring.

Safrane posted this link https://www.sportsmaserati.com/inde...-from-front-speakers.14277/page-2#post-342684 which says you can bypass the amplifier by connecting the two plugs together where the amp loom plugs into the main loom.

It seems to me that on mine (3200GT) the amp connector is part of the main loom and the can't by bypassed?

Does anyone know where the two plugs are, the linked post says towards the front of the car??

 

[Zep]

I had an issue with my Becker where it would make random pops through the speakers even when off. The pops were regular and quite loud. I reckon a capacitor was breaking down. Cured with a new Alpine HU.

 

[safrane]

Post 35 here shows the cable i mentioned.

https://www.sportsmaserati.com/index.php?threads/stereo.14921/page-2#post-465587

 

[Oneball]

I had an issue with my Becker where it would make random pops through the speakers even when off. The pops were regular and quite loud. I reckon a capacitor was breaking down. Cured with a new Alpine HU.

Thanks Zep but I’m pretty sure it’s not the head unit, although I have got a new one, as it’s still making a noise and the dash looks like this.

 

[Oneball]

Post 35 here shows the cable i mentioned.

https://www.sportsmaserati.com/index.php?threads/stereo.14921/page-2#post-465587

Thanks Safrane. Mine isn’t like that the connector from the amp goes straight into the main loom and then through into the passenger compartment. Which does surprise me as the amp was an option so I’d have thought wouldn’t be part of the main loom.

Having said that I could be talking drivel and those connections are behind the amp bracket. Will look later.

 

[conaero]

From days gone by, I seem to remember you could buy a suppressor that connects to the back of the head unit to stop this exact thing.

May be worth some Googling.

 

[Zep]

Thanks Zep but I’m pretty sure it’s not the head unit, although I have got a new one, as it’s still making a noise and the dash looks like this.

View attachment 51797

That pretty much rules that out then!

 

[a2ruedas]

I had random strange pops and crackles from my door speakers after dismantling my passenger door card to repair the lock mechanism. This would happen with the engine and stereo both on or off.

It turned out to be the speaker or wire earthing out on the door chassis when the speaker screws were tightened... I had evidently refitted it in a slightly different orientation. Some fiddling with wiring and reorientation of the door speaker remedied the issue.

May be worth a look of you've had any of the door cards apart recently...

 

[Oneball]

The amp connector is part of the main loom so there doesn’t appear to be an easy way to bypass it which does surprise me as I wouldn’t have thought the whole loom would be a specific item for an optional extra.

Got the amp apart and can’t see anything obvious.



Thanks a2ruedas I’ll have a look.

The thing that really worries me is that there’s a short somewhere in the loom.

Off to play with my knobs

 

[Oneball]

New radio in and it’s still the same.

Crackle seems to be front speakers only and there’s no music coming from them too. Just can’t remember if that’s what it was like before I changed the head unit. I’ve unplugged the door loom on one side and then the other and it makes no difference so I don’t think it’s as a2ruesdas suggested.

Just wondering if there’s a way of determining if it is the amp or if I shiiulf just change it and see.

New radio and non sticky buttons.

 

[TimR]

As suggested, try a suppression condenser...

 

[Oneball]

As suggested, try a suppression condenser...

Thanks but I’m not sure how that will help. It makes the noise with no head unit attached. Plus as there’s no music coming from the front speakers but there is a short crackle there has to be a fault in that circuit alone. It’s just whether it’s in the loom or the amp that’s the question.

 

[a2ruedas]

Great effort on the sticky buttons, I'm working through mine also. What process are you using our of interest?

 

[Oneball]

For the three knobs and the window switches I disassembled them, scratched the goo off with my nail then carefully cleaned with cellulose thinners before painting with Tamiya matt clear. The buttons weren’t too bad and I was worried about taking the markings off so I cleaned them with thinners and painted over the soft touch. Which I don’t think is going to be very hardwearing but it’s no longer sticky.

 

[Oneball]

OK, can anyone explain this:

Thought I'd start with the basics, check continuity to the battery.

With +ve disconnected body to -ve battery terminal 0 ohms, all good so far

With battery connected:

-ve to any part of the body 5 ohms

-ve to body with one interior light on 18 ohms with all interior lights on 30 ohms, with engine running no continuity between body and -ve terminal

Why is the resistance between the body and the -ve terminal of the battery increasing when electrical load is added?????

 

[Zep]

Your multimeter measures resistance by passing a fixed current through the test piece and then measuring the resulting voltage. It then works out the resistance using Ohms Law.

When there is already current going through it is frizting the calculation.

 

[Oneball]

Thanks, just me being thick!

I've got the analogue one out and it's reading ok

 

[TimR]

Thanks but I’m not sure how that will help. It makes the noise with no head unit attached. Plus as there’s no music coming from the front speakers but there is a short crackle there has to be a fault in that circuit alone. It’s just whether it’s in the loom or the amp that’s the question.

Is the amp off at the time ?
Condensers are built into modern amplifiers to suppress contamination. Im guessing it may not be true of the OEM amp... ?

 

[Oneball]

Thanks. If the amp has power it crackles, I’m not up on ICE, maybe the next thing to look at after sorting this:



WTF??!! It’s bypassing the side of the relay that provides power to the HVAC, wipers etc. All the stuff that causes the crackle. Need to get a new relay to put in and see if it makes a difference.