I have a 2000 773 turbo with 1500 hours. The other day I noticed that I have a faint steady high pitch whine coming from the speaker on the bottom of the left upper panel. I believe that this speaker is there to notify one of problems with the machine. This whine is coming thru both with the key on or off. I pulled the two wires off numbered 2930 which I think is ground and 9320 which is power, and it stopped. I lifted the cab checked all wiring, and cleaned the main harness ground, but it still exists. There are no codes coming up in the display, but there must be power coming from somewhere for some reason. Any one have any ideas?? Thanks John
wow, thats a new one... the alarm gets it's signal from the controller through the LH panel via the 9320 purple wire. all purple wires are communication. 3 places i would look for harness damage LH panel, where the harness goes behind the panel mount if the machine has HVAC check behind the HVAC panel, i've seen the harness rub against the mounting screws for the panel. area in and around the cab/mainframe harness connector. you may have a bad panel, or the controller may be causing the problem :drinkup
Agreed, can't say that I've ever seen that before. :beatsme
Is it possible that what you are hearing is alternator whine? You could add a ground wire to the alternator housing & then ground that to the machine's frame. Try that out with a set of jumper cables. Only use the negative cable to the alternator on one end & to the battery negative with the other. See if that helps or rids the machine of this issue all together. I hope that is all you need.