Thread: Buzzing in car stereo....cant nail it

Tweet

Are you using double shielded RCA leads to your amp? Are you running the RCA and power leads on opposite sides of the cabin? If they are too close, noise can enter the RCA leads from the thick power leads.

The car car got new plugs and leads about 18 months ago.

I havn't tried the capacitor idea yet, i've just got back from holiday. However during the trip away, I connected a Sony discman to the rca for the rear speaker amp and connected the ignition wire to the remote wire to pull the amp on. The discman ran on batteries and it all sounded primo.

Its something effecting the headunit. However I dont think its a sheilding problem.

I'll have a crack at the big cap idea and maybe resistor spark plugs. I think they are anyway, there was an R in the model number. Grabbing straws perhaps.

when you find the problem I bet you will kick your self for it.lol

just for the sake of things, have you tried removeing one plug wire at a time and Examine all plug wires and boots for insulation damage, burn or melted marks or loose connections.

next try Measureing the resistance of the ignition coil secondary wire (high voltage wire). The resistance should not exceed 7000 ohms per foot (30cm). and Inspect the ignition coil for damage, cracks or carbon tracking. Push the connector tabs and separate the wiring harness connector from the ignition module. Inspect the harness and connector for signs of dirt, corrosion or burn marks.

and check the coil itself Measure resistance from the coil negative(-) terminal of the primary connector and the high voltage terminal of the coil. Resistance should be 8000-11500 ohms.
and look for signs of arching.

also making note that the positive and negative terminals are not backwards, a coil can still fire if this happens .

If the coil primary leads are reversed, the voltage required to fire the spark plugs is increased by 40%. The coil output voltage is directly proportional to the ratio of primary to secondary turns of wire used inside the coil.
this increase on a stock type plug wire can cause RF noise in a radio.

You don't by any chance have a fibreglas hood on there, do you? They don't shield any interference.

noop...good ol' Ozzy steel....and rust,it had good ol' ozzy paint sadly

try the condinsor. also a grounding problem.you can also buy a filter to stop that from your local eletronics store

In answer to your question...MFD is Microfarad Uf Ultra Farad is the same as Microfarad. MMFD or UUf is also called Pico Farad (Pf) The capacitor in your distributor is only 5 MFD, it has to be able to charge and discharge very quickly. You want a 2000 or better MFD for the radio, you want it to hold a charge longer. That's what does part of your filtering. The coil of wire does the rest. Simple basic electronics...Capacitors pass A.C. and block D.C...Coils block A.C. and pass D.C. By the way, the ignition coil is misnamed...it's actually a step up transformer. Now the spike that you hear as a buzz or whine is an A.C. spike. The capacitor connected between Hot and ground will pass some of the A.C. spike to ground, The coil connected in line between the hot and the radio will suppress the A.C. and pass the D.C. power to your radio. Does this help you to understand how it works?

Sorry Xentrix,
I just realized that you're in the UK. A Microfarad is equal to .001 Farad. A MMF Micro,microfarad or Millifarad or Picofarad is equal to .000001 Farad. You may not have a Radio Shack store in the UK. Go to an electronic repair shop and tell them your problem. Tell them that you need a RFI filter or a Capacitor and Coil filter. They'll know what you need. An auto repair shop will tell you that you need an expensive tune up. When they're through and you still have the noise, they'll tell you that you have a bad radio.

Cheers guys. Ha! the UK? guess again. I'm from New Zealand but our steering wheels are on the same side as the UK.

I went to a lectronics store and bought a 3 wire 40 amp noise suppressor. When I got it home it had no instructions to install it. I gather the black lead is a ground. Some guys at work said it goes between the coil and the distributor. Its a biggish thing with heavy leads. Any ideas on install?

....I mean Australia. They are our neighbours, and our supplier of big 6 and 8 cylinder family sedans and wagons.
The little b&w pic under my name has the 79 & 82 Ford Falcons from Oz in it. These are the same as mine but not my actual cars. Oz makes good beer and a nice place to go on holiday too. Cheers. Phil.

That is true... Being Australian is great!

You guys get many of our Toranas over there??

Take all the Falcons you want!

Just kidding, New Zealanders are great people and I would love to visit the country some time. I have seen a lot of tough cars in mags which were built in New Zealand... and they're not too bad at Rugby either.

Toranas are getting thin on the roads over here as is Valiants. An Australian car day will bring out some primo Toranas, Vals, Leylands and Falcons, but they are pleasure craft these days.
In fact anything 70s is nearly all gone unless it was collectable or loved be it Oz, English or Japanese. New Commodores and Falcons are everywhere.
Not to bad at Rugby!...HA! The best!

Xentrix,

If memory serves me, the black wire is ground. The other two go between the power source, (fuse box) and the radio hot lead.

....just buy the weight of the leads and the 40A rating. It's kinda on hold a little bit at the moment now due to a funny noise in the diff. I can't believe at 200ci could wear out a bearing in an open centre diff that gets driven like a grandma.