New radio showing engine interference

[Timbuick]

Thanks for more suggestions. I need a new belt, so i can try that. I did try a separate earth from the unit to chassis, but to no good effect. Antenna is non oem and not electrical.

 

[garyk1970]

if you had no noise with OEM stereo then the car isn't the problem, I'm suspecting...
reconnect OEM stereo and retest...if no noise,fab out a ground cable with an ring terminal on each end...and bolt one side to metal in dash,the other end to rear of kenwood IN ADDITION to the OEM ground wire....
if this doesn't help,try another stereo...

 

[datant69]

when regrounding try this

i've seen this overlooked and i wouldn't think a isolator would work well but may. My suggestion would be to use a compression O ring and good sheilded wire run it under the dash find a good solid place around your sterring wheel that is METAL, take alittle sandpaper and take any pain, rust or crap that may cause any interferance and ground it with washers nuts and bolts. try this it's simple and if you don't have a grounding loop then it should cut out any noise. Did see any info on amps and stuff so i'm guessing you don't have a complete system? if so was this noise present what so ever before the R&R of your previous head unit? and don't take the neg completely outta the loop. true your antenna is grounded but it's too long and not a proper ground. Just letting you know my 02 buddy good luck

 

[Timbuick]

Thanks again, the stereo ran just fine in my other car and is quite new. I have run an earth from the chassis of the head unit to a good metal ground without luck. I have the noise suppressor and will try that next.

 

[datant69]

try the sanding down thing i mentioned

it's not hard but it may just need a good ground that is scoffed with sand paper and just make sure it's done tight. i've been doing installs since 85 and normally engine noise is a bad ground. just do me a favor and try it if you want a cheap resolution since it wasn't mentioned about the sanding down part. just make sure you get it down to the bare metal if it has paint or rust. couldn't hurt and it's worth a try.

 

[newtownhood]

my dad has been in the car audio field since the 70's and suggested their might be a dried up capacitor inside the alternator. The alternator would charge fine, but would send a dirty signal. I guess you could ask an alternator shop if they could get you the part, I'm guessing it would be super cheap. I'd throw some new brushes in at the same time.

 

[TurboBuRick]

my dad has been in the car audio field since the 70's and suggested their might be a dried up capacitor inside the alternator. The alternator would charge fine, but would send a dirty signal. I guess you could ask an alternator shop if they could get you the part, I'm guessing it would be super cheap. I'd throw some new brushes in at the same time.

Good advice that has already been mentioned.

 

[newtownhood]

actually that was a diode branch mentioned earlier, not a capacitor. Diodes keep things DC, they don't act as filters. Thank you, come again.

 

[TurboBuRick]

actually that was a diode branch mentioned earlier, not a capacitor. Diodes keep things DC, they don't act as filters. Thank you, come again.

Fix the alternator.

 

[garyk1970]

Please explain how the oem radio had no noise,and now the car/alt/grounds are suddenly the issue?

 

[TurboBuRick]

Please explain how the oem radio had no noise,and now the car/alt/grounds are suddenly the issue?

Later model after market radios have more power (built in amps) that will magnify issues with ignition, charging system and or bad grounds.

This was a bigger problem through the early 90's with the addition of external amps. You could here the alternator whistle through the speakers. They have gotten better through the years with suppressing the interference. Thats for sure but non the less we can still see interference issues if there are other problems. I.E. bad grounds, alternator and/or ignition.

my o2 fwiw

 

[Timbuick]

Well I now have the noise suppressor to try at the weekend. Suspect the alternator tip may yet be the issue. Glad it has sparked lots of interest!

 

[Timbuick]

OK guys, reporting back. See what you can make of this!

Decided to try a noise suppressor first. Wired it as instructed and the first thing I noted was that the stereo was nonw 'live' even with ignition switched off. Presumably, the noise suppressor connects the two live wires internally (switched live and battrey live). Anyway, I turned on the engine and the interference continued, the supressor made no difference.
I then started to disconnect it; as I did so there was a quick flash as I reconnected the switched live wires. At this point the suppressor was still connected to earth and the live battrey feed.
I then removed the suppressor completely and with the oem wiring to the stereo reconnected found that the unit was dead. The live feeds were not live anymore.
I checked both the radio fuse in the fuse box and the in line fuse from the stereo and both were fine. Stereo still dead.
Finally, I notice that the seatbelt alarm circuit was not beeping at me with ignition on.
So, what on earth happened and why is the live feed to my stereo dead and the belt alarm also dead??

ps I quickly wired the stereo into my old Mopar and it worked fine, so what happened with the Buick?
Thanks for reading if you got this far!

 

[newtownhood]

you blew the clock/domelight fuse. I bet your domelight and cigarette lighter aren't working. How many leads are on this noise supressor? Most have a blue,a red and a black. Blue goes to the radio,red goes to 12V switched and blk goes to ground. I've never seen one that goes to the hot and the switched leads...

12V constant:
kenwood-yellow
adapter harness-yellow
car-orange

12V switched:
kenwood-red
adpater harness-red
car-yellow

just see if you're getting power at both of those leads.

 

[jimski]

Replace the head unit with another.

 

[Timbuick]

'Newtown..' thanks for that. I lost my broadband for a few days!
So, in response to your post, yes I lost the courtesy lights and seat belt alarm noise.
Just a quick question on wiring the suppressor as the instructions on the item were vague.
The blue wire to the radio, which colour/function wire should I connect this to?
I understand how the red and the black wire connect.

 

[GNRick]

Blue wire on radio might be power antenna wire. Run your wires (speakers and amps) together down passenger side of the car. Zip tie them together every 12 inches. Use 24 gauge twisted wire in a shielded jacket to connect the head unit to the amps in the trunk. Don't worry about the wire being too thin. It will work fine. You can use Belden 9681 which has 4 wires in the jacket. http://www.newark.com/belden/9681-060500/shld-multipr-cable-4pr-500ft-300v/dp/04F5159 However, you will find that this wire is nearly impossible to find in less than 1000 foot rolls. However, you can get it on Ebay for $13 for seven feet (you will probably need two of them) or Walmart for $20 for the same package. Unfortunately, the Monster Cable at Walmart or Ebay is a single wire, not four wires. Let's assume you have 3 amps. One amp for the front speakers, one for the rear speakers, and a subwoofer amp. The subwoofer amp takes a mono signal, so you will only need one wire from the head unit. So to do three amps in the trunk, and needing four wires per amp (only two for the sub amp), will come to 10 wires. At $13 per wire, it will cost $130 to wire all three amps. Buy 10 of the appropriate RCA adapters (1/8 inch plug in and RCA out) and 5 double female connectors (to connect the two cables together) at Radio Shack and your engine noise will disappear. Monster Cable AI 800 MINI-3 Mini Cable - eBay (item 310300208996 end time Apr-30-11 09:29:16 PDT) If you still have engine noise, go with a thinner speaker wire.

 

[GNRick]

Good news is you can use the factory ground wire in the dash.

 

[GNRick]

100 ft. for $16

:smile:I found the cable, and cheap too-

Dayton Audio MLI-100 22/2 Shielded Mic/Line Cable 100 ft.