Rick Carter

I know what this is by name, can someone explain to me how it works as a relay. It is in position 18 in an 85. Do they go bad, is it checked the same as the other relays? Is it a relay in name only?
Thanks,

jeff jackson

Don't know for sure....but I believe it supplys voltage to the noise suppression choke (looks like a small transformer) under the passenger side carpeted cover with the amplifier under it. Actually, after checking the wiring schematic, there are 2 noise suppression chokes in the circuit. 1 between the ignition switch and the radio...and the other between the fuse (#28 on my 86.5), and the booster amplifier.

WallyP

The supressor absorbs the kick-back from the A/C compressor clutch.

Rick Carter

Does the suppressor relay have connection to one or both of the suppression chokes in the circuit?

How does the supressor absorb the kick-back from the A/C compressor clutch, is it the relay supressor or a supressor the relay controls? Can the circuit be modified to absorb interference from an electric fan?

Thanks,

dfroelicher

From how it seems to be wired, off the ignition circuit, it should, or at least could be rewired to filter all incoming power to the radio unit and or the amplifier.

a noise supressor is just like an equalizer for sound, just for energy in this case, it takes the incoming wave and modifies it according to a bunch of resistors and capacitors. Normally, it filters out any 60hz ground cycle and any voltage spikes or drops to smooth out the incoming power thus creating a clean power source and no background noise in the resulting audio.

jeff jackson

One is wired in the power circuit from the ignition to the radio...it is intended apparently to choke battery noise from the charging system. The other is wired in the power feed to the booster amplifier, and as Wally alluded to , looks to suppress electrical interference noise from the AC clutch.It looks like the noise suppressor choke for the booster amp and filter noise from the AC clutch is tied to the Central Electric panel, and probably is the one the relay is referring to.

Alan

To answer the original question - no its not really a relay - it just uses that type of socket and is mounted where all the others are. You cannot test it like its a relay.

I believe its just an inductor but I've never taken one apart.

Alan

Mark Stahl

Is it possible to replace the stock amplifier with an aftermarket unit, bypassing this noise suppression choke device, and still avoid alternator whine, A/C clutch, wiper motor, seat motor, etc. feedback?

Alternately, if you were installing a new audio system could you use this device? How? Would it be a good idea to try?

RicerSchnitzzle

You will only get the hum if you have ground loop issues. You can install an entire aftermarket system with out noise if you use a good common ground. After market noise suppressors are just small capacitors. Most aftermarket amps have good enough capacitors inside to not generate any noise, however the original signal from the head unit is another story. That's were the source noise comes from. Head units don't have good built in noise suppression. Any noise filter will work well, though the real key is choosing a better ground path. You can also instal a large 1/2 farrad or larger cap with the amp and it should steady all systems in the car.

My system shares on complete power and ground path seperate from the other systems in the car. It's devoid of all whines and hums.

Mark Stahl

Thanks for the reply. The reason I ask is that I currently have a bit of alternator whine in my system that I'm trying to trace. The HU (a Kenwood Excelon unit) does take both switched and constant power from the car's wiring, but the ground is run to a common ground with the amp -- a newish, though not exactly high-end model (American Legacy 4ch.) in the rear of the car. So far, ground loop isolators placed between the HU and the amp have not worked and neither did a cheap-o power filter on the HU (or amp).

Would a separate 12v power line from the battery to the HU help? Any other suggestions? Someone suggested twisted-pair audio patch cables from the HU to the amp (I did notice some change as I rerouted that long ground wire, but not enough to eliminate the noise completely).

RicerSchnitzzle

Twisted pair RCA cables are more of a gimmick than anything else. (90% of high end audio is..)Anytime a signal wire crosses a power wire you can get interference. The trick is not to route power and signal wires together. I run power and ground down one side of the car and RCA's down the other.

A dedicated power and ground from the battery to the head unit should help, but I would try different ground points first.