Autocom Problem

[teejay]

I had a new sound system fitted to the bike last year and I have noticed that now, when the radio is switched off but the bike is running, you can hear what sounds like interference from the spark plugs. When switching the radio on this sound disappears. Anyone got any ideas ?
Regards
Terry

[myk_edwards]

Which autocom are you using, and how have you got it wired?

Is the power from the bike or from batteries? You could eliminate the bike power from the equation and install a drycell and try that. then you could look at putting a choke ( suppressor) in the power line from the bike to the autocom which might eliminate the noise.

Is it also wired to the rear speakers? you may have got the earth's crossed, which could also cause the problem?

[autocomtom]

Mike has made some good points here but some others to consider;

It would seem that with the radio switched on you get a load across the speaker wires which is enough to help suppress the excessive HT noise on the speaker wires, however when the radio is switched off this load seems to go away.

A solution could be to fit a 100 ohm resistor between left+ and earth and another across right+ and earth to the isolation block, to the side where the wires go to your Autocom system.

If you post the music lead back to me I would do this for free, but it’s a pain to remove it from the bike, so can you get the bike to me, if not get someone who knows one end of a soldering iron from the other to give Autocom UK a call and we can talk them through this.

Autocom-UK-Tom

[teejay]

The unit in question is an Autocom Pro. I had it fitted by BMW Manchester when I bought the bike but I think it's hard wired into the electrical system.
Regards
Terry

[autocomtom]

Terry

If you can get down to our factory I will sort this all out for you.

Tom

[teejay]

Thanks Tom, hope to when weather warms up. Thanks for everybodies input.
Regards
Terry