High pitch noise from stereo when engine is running.

[1PuntoCarl2]

Hi there,

A recent problem has just started and its annoying while driving about...

A high pitch whining noise coming from the headunit when the engine is on. It sounds like interference with the rca's and power cable bit they're ran down different sides of the cars so cant be that.

The whining noise stops when the engine is off and i also found out when i use anything electrical inside the car the whining noise gets quieter.

I thought it could be an earth problem of some sort but not too sure where.

I also read about pioneer headunits having some earthing problems on the actual headunits at times so it could be something similar?

this is a clarion headunit. any suggestions as to what it would be?

Thanks,
Carl.

 

[jip0]

does sound like an earth issue

start by checking and cleaning up your amp earth and then the other common ones

 

[1PuntoCarl2]

hmmm but surely if it was the amp then the high pitch noise should still be there when i turn the ignition off as the amp is still being used?

 

[Davren]

Alternator brushes may be arcing. A radio suppressor on the alternator output terminal may stop the interference.

 

[1PuntoCarl2]

Alternator brushes may be arcing. A radio suppressor on the alternator output terminal may stop the interference.

to be honest i did have a bit of squeeling from the alternator belt a few weeks ago, it had all stopped though. so what are these alternator brushes?

Ive just found out about wrapping copper wire around the rca outputs of the headunit and earthing it to the HU :\

 

[Davren]

Alternator brushes are sprung loaded copper/carbon rods that conduct electricity to rotating copper slip rings inside the alternator. Because they form a moving electrical contact, small sparks can occur which can cause radio interference.

Most electric motors and generators/alternators have brushes so radio interference can also be caused by a car's radiator fan motor, wiper motors, window lift motors, heater fan motor etc. The radio interference would only be noticable while the motor or alternator was running.

Radio interference can also be caused by the sparks from a petrol car's ignition system, but that usually manifests itself as a crackling noise on the radio, not the whining noise you describe.

 

[wilko1992]

What you want is one of theas : http://www.ebay.co.uk/itm/GROUND-LO...173?pt=LH_DefaultDomain_3&hash=item2311f3690d

I had a similar problem with my last amp, so i got one of theas and never had the problem agen

 

[1PuntoCarl2]

'Most electric motors and generators/alternators have brushes so radio interference can also be caused by a car's radiator fan motor, wiper motors, window lift motors, heater fan motor etc.'

When i use internal electrics such as electric windows the whining noise decreases though. At the moment I drive around with my demister on as it dramatically reduces the noise whereas that states internal electrics can cause it.

Also, if it was a bad earth then surely the whine should constantly be there even when the engine is turned off?? my guess is the ignition interference like you also said. The radio signal does crackle alot too, especially when on idle, but when in motion its not as bad.

 

[1PuntoCarl2]

What you want is one of theas : http://www.ebay.co.uk/itm/GROUND-LOOP-ISOLATOR-GOLD-PURE-SOUND-NO-INTEFERENCE-/150625020173?pt=LH_DefaultDomain_3&hash=item2311f3690d

I had a similar problem with my last amp, so i got one of theas and never had the problem agen

did you run your power cable and rcas down the same side of the car?

 

[wilko1992]

they was all down one side but since i upgraded my amp to a better make i havent had no problem so i just unpluged my ground loop isolator and still no problems

 

[1PuntoCarl2]

they was all down one side but since i upgraded my amp to a better make i havent had no problem so i just unpluged my ground loop isolator and still no problems

thats probably why you had a whining noise because the rca's were picking up interference from the power cable.

its none of my amps, speakers or sub making the noise its just the headunit when the engine is ticking over. also has a really bad signal too. Might have to take it to an auadio specialist tomorrow.

 

[wilko1992]

i dont have no interferance any more and i havent even moved the cabels

 

[1PuntoCarl2]

when you used to have interefence was it coming from the headunit, amps or speakers? If it was the headunit I may do a cheeky little £3 purchase lol

 

[wilko1992]

i had a whistling noise through my speakers.

 

[1PuntoCarl2]

i had a whistling noise through my speakers.

yea i used to have that in my saxo (back in the chav days lol) because i ran all my cables down one side and the rca's had interference from the power cable.

 

[wilko1992]

but since i changed my amp for a better one the whisteling noise has gone so iv unpluged the ground loop isolator and still no whisteling noise so think it was due to a crappy amp