1200 GS Whinning being picked up thru autocom - Help?

[Growler]

I've searched the threads far and wide and can find no other reference to a whinning problem on the 1200GS. It started about a week ago. I have had Autocom installed on the bike('05 GS1200) for about 6 months and have been using it without any problems using a Motorola GP360 radio to talk with others. The autocom is wired into the rear of the under seat Aux socket and the radio is powered via an additional Aux socket fitted to the TT dash cowl. The dash socket is powered from the BMW GPS at the left side of the head stock. All this worked no problem at all until the bike was serviced last week.

Since then any transmissions I make are virtually unreadable through a combination of static and screeching. I've tried every possible solution with no success... If I power the radio via its own battery there is no problem but as soon as I power it from the bike the problem returns. Coincidently the bike appears to be making a slight whinning noise (similar to an altenator whine) which increases with the engine speed. I've compared my bike to a mates 12GS and he can use all my radio equipment with no problem but as soon as I tried his gear the problem continued. His bike did not have the whine...

Autocom suggested the possibility of an earth loop in the system but were unable to supply a lead for the GP360 to combat it. Given the system all worked a week ago I don't think this is the problem but could be wrong (and often am!)

My only guess at the moment is that the Frequency of the whine is similar to that of the radio and therefore causing the interference... This prompted me to try an inline suppressor at the rear of the dash aux power socket. This reduced the noise making my transmissions readable but still with a lot of interference and nowhere near as clear as they have been..

Does anyone have any suggestions. The bikes going into the dealers first thing on Monday as I'm off to Stelvio/ Lake Garda on Tuesday! but any help or advice would be very much appreciated as I'm stumped and ready to bin the whole intercom idea!

 

[Pukmeister]

Mine is doing the same, it goes when I unplug the audio lead from the GPS unit to the Autocom (the audio lead is fed through an earth isolator unit). I haven't got any further with my diagnosis yet as the GS is in bits awaiting a rear drive unit repair. Perhaps you could unplug the audio inputs one at a time and see if it clears to narrow things down a bit ?

 

[GrinningGSer]

My whine started when I plugged my sat nav into the autocom- very well sorted by an additional autocom part:
here

 

[jeff garnett]

Hi
if you are passing Manchester on Tuesday I can lend you an icom radio & lead to power the radio of the Autocom this may fix it, my Autocom & GPS work OK.
jeff

Jeff0[!at]breathe.com (replace the [!at] with a @ )

 

[Gonz]

Is your autocom attached to the owner's manual bracket thingy infront of the battery?
Try moving it from there. Others have got joy from that (I dunno why, perhaps isolation from induction is required) Audio or power isolation is needed for your radio. I'd try and use batteries if Autocom dont have one for your model.
As a temporary measure. Try and get power for Autocom via a fused connection directly to the battery. In case after the last service (prog. update) the software update is screwing with things. I use the tail light circ. for the power. Earth directly to the battery.

Gonz.

 

[Growler]

Thanks for the advice.. I've already tried wiring the Autocom and the radio direct to the baterry via a fused connection both seperately and together with no success. The noise is only present during radio transmissions and I don't hear it, only others I transmit to. I pick up their signals with perfect clarity, similarly music is played through the system no problem at all. The only way I've managed to eliminate the noise so far is to run the radio off its own battery but unfortunately its not aa batteries but its own specific battery and the cells are on their last legs so batteries only last a short time due to the power output of the radio..

The autocom unit is housed in the the tool tray and I've also tried moving it around the bike without any joy. Will keep pluggin away at it and I'll let you know if I get any success. My suspicion at the moment is the altenator whine so maybe a strip down and grease this morning is called for!

Jeff thanks for the offer of the Radio but I'm leavin via Rosyth on Tues but much appreciated anyway.

Worst case scenario I may just purchase a cheap battery powered Argos PMR to tide me over this week!

 

[Dutchman]

..............I'm leavin via Rosyth on Tues but much appreciated anyway.........

Me also.......similar destinations too, via Pirmasens in Germany.........if you need a drinking companion on't ferry, I'm your man..........

See you in the queue......

Cheers

Dutch

 

[birdseye]

You say that if you power the radio from its own battery you get no problem ie the spurious noise is coming up the 12v supply into the radio. This suggests that the problem is the dash socket and its associated wiring, probably something disturbed or damaged when the grease monkeys were servicing it. You could try returning the bike to the dealer and complaining but its highly unlikely that tyhe dealer has any more knowledge of electronics than you have. So anything they do will be by guess or by god.

have a good look at the socket and the run of the wiring connecting it. Wires can pick up electromagnetic interference simply by being close to another wire.

Double check any nearby alternator or ignition wiring - both generate electromagnetic noise if not 100%.

As a cure, go to Maplins and buy a ferrite or two (cheap) - little ferrite rings which you can clampo round the power supply wires to your radio. These will stop increase the imperdance of the 12 supply wires to the sort of AC signals you are hearing.

 

[Growler]

Thanks to all.. didn't get near the bike today so it's over to the dealer first thing tomorrow.

if you need a drinking companion on't ferry, I'm your man..........

Dutchman, our paths will cross in the bar I'm sure! Looking forward to it

 

[themadprofessor]

If this noise only occurs when transmitting it sounds like RF from the radio getting into the audio circuits and then causing RF feedback (sort of anyway).

This can occur due to poor earthing or to proximity of the microphone cables to the transmit aerial.

Apart from the service have you relocated the antenna? Otherwise look for poor screening/earthing on the audio cable from the radio back to the autocom. Also look for a poor earth on the power socket on the front of the bike where you are picking up the radio power.

Just a few thoughts, Chris

 

[Mike L]

or it could be an earth loop. had a similar prob with roadangel connected to autocom. Try cutting the earth at one end of the radio interconnect cable. The other end is still connected to earth so the screening will still work.

hope this makes sence.

Mike

 

[Growler]

Sorry haven't had a chance to post however I didn't get the issue resolved prior to departure. The dealer has diagnosed the whinning as a main case bearing and currently has a new one on order however thats been 2 weeks. Had to take a chance and leave for Italy with bearing still whinning. All was going well until we reached Lake Garda and the clutch started slipping in top gear! Managed to nurse the bike home via a few mountain passes but I'm now a bit disappointed with the bike. It's done 5000 miles and has had two major mechanical faults. This isn't what I expected from a £9k bike and certainly not a BM.. the bikes been with the dealer for a week now and the clutch is also on back order so should be another week at least.. Hopefully when I do eventually get the bike back I'll get to the bottom of the intercom problem.

One thing I will be doing is changing the way the Autocom is wired. I currently have it soldered into the rear of the accessory socket however when the bike was getting hot abroad (Temps in excess of 40 degress at times!) it was shutting power to the accessory socket down killing autocom. I know some have said there is a software update due to cure this however I spoke to autocom and they now advise taking a switched live from the front light(the small parking light) and the earth to the battery.

All in all it was a great trip and the bike was fantastic on the twisties just a shame about the technical problems as they did put a bit of a damper on things for me. Will let you know if I get to the bottom of the radio probs.. Cheers

 

[JayGee]

Sorry haven't had a chance to post however I didn't get the issue resolved prior to departure. The dealer has diagnosed the whinning as a main case bearing and currently has a new one on order however thats been 2 weeks. Had to take a chance and leave for Italy with bearing still whinning. All was going well until we reached Lake Garda and the clutch started slipping in top gear! Managed to nurse the bike home via a few mountain passes but I'm now a bit disappointed with the bike. It's done 5000 miles and has had two major mechanical faults. This isn't what I expected from a £9k bike and certainly not a BM.. the bikes been with the dealer for a week now and the clutch is also on back order so should be another week at least.. Hopefully when I do eventually get the bike back I'll get to the bottom of the intercom problem.

One thing I will be doing is changing the way the Autocom is wired. I currently have it soldered into the rear of the accessory socket however when the bike was getting hot abroad (Temps in excess of 40 degress at times!) it was shutting power to the accessory socket down killing autocom. I know some have said there is a software update due to cure this however I spoke to autocom and they now advise taking a switched live from the front light(the small parking light) and the earth to the battery.

All in all it was a great trip and the bike was fantastic on the twisties just a shame about the technical problems as they did put a bit of a damper on things for me. Will let you know if I get to the bottom of the radio probs.. Cheers

Another possibility is the routing of the PTT cable, get that near alternator/rectifier or other HT leads and it will pick up interference. This cable might have been disturbed during servicing, as mine was and rerouting it cured the problem. Sorry to hear of your clutch and main case bearing, (it's a pity the GS isn't made by Honda!)

 

[Growler]

Yeah I did think about that as the system doesn't have PTT but there is a radio extension cable which runs under the tank and may have been disturbed...

Have to agree about the Honda comment.. having run a VFR for 3 years with no problems this is taking a bit of getting used to... I believe they call it character!