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Topic: Buzzing noise from dashboard question. (Read 410 times) previous topic - next topic

Buzzing noise from dashboard question.

This morning we noticed that there was a very subtle humm/buzz from inside the dash board that comes on every minute or 2.  Seems somehow related to the BOOST switch on our 1997 U270 36' coach.  Goes away when the BOOST switch is engaged (red light on) but starts cycling every 2 minutes when the BOOST switch is in the normal position.  Not sure if this just started as we have been away for a month (with the coach plugged in) and most of the time the A/C is on so maybe I missed it.  Is there a relay that could be stuck/failing?  Can I just leave the BOOST switch on 7/24?  Note that I do have a small 12v 3 amp Battery Tender charging the 2 starting batteries as they are old/weak but for now we are parked and not traveling.  With or without the Battery Tender attached the hum/buzz persists.....any one had this happen.  One thing I did not check is if the problem persists when the coach is unplugged from 50amp power....not that that is an option in 99 degree Alabama heat.

Thanks!
Carl and Kathleen
Killeen Texas
1997 U270

Re: Buzzing noise from dashboard question.

Reply #1 –
Carl,

This is out on a limb or a real WAG.
Did your coach come with a low battery generator auto start?
If so it could be sensing low batteries causing it to try to start the generator.
For this to be possible someone would have had to disconnect the wire to the generator and left the sense wire hooked up or you would hear the starter engage on the generator.

Mike
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: Buzzing noise from dashboard question.

Reply #2 –
Quote from: Pamela & Mike –
Carl,

This is out on a limb or a real WAG.
Did your coach come with a low battery generator auto start?
If so it could be sensing low batteries causing it to try to start the generator.
For this to be possible someone would have had to disconnect the wire to the generator and left the sense wire hooked up or you would hear the starter engage on the generator.

Mike
My 97 U270 the Gen switch has Start-Off-Auto. 

a couple of things you might try is to switch it to Auto  and see if it tries to start.

also make sure you have over 1/4 tank of fuel.
Steve

1997 U270 36' build 5179
Motorcade #18147
1980 CJ5

Re: Buzzing noise from dashboard question.

Reply #3 –
Problem solved.... turns out the OEM Sony Radio was giving off the noise and when I wiggled the plug on the back of it the noise changed-I could actually feel the buzzing.  So....we never use the radio/cassette deck so I backed the plug out a bit and no buzzing-fixed.  We don't have an auto start  gen and I can't explain why the boost switch position effected the hum but it is now gone.

Thanks!
Carl and Kathleen
Killeen Texas
1997 U270

Re: Buzzing noise from dashboard question.

Reply #4 –
On my upcoming trip i am going to take out that old Sony.  I am taking my sawsall with me just in case "LOL"
Steve

1997 U270 36' build 5179
Motorcade #18147
1980 CJ5

Re: Buzzing noise from dashboard question.

Reply #5 –
I have a use for old stock Sony radios.  Let me know. Texhub@gmail.com
1999 U270 40 #5518
USN. USPS.