Brightening my panel lights affects my gauges

[wpbarnar]

'97 Encore.    Adjusting the rheostat to increase the panel light brightness, makes the fuel level and oil temperature gauges dip or decrease slightly.  The glare shield lighting rheostat does not affect the gauges.  There is also a high pitch whine on Bose headsets connected via a lemo jack that increases with panel brightness.  I and others are thinking this a ground problem.   Any help out there leading me to a specific ground point?   Or is it possibly something else and I am jumping to conclusion on the ground.

Bill

 

 

[laytonl]

Does a heavy load such as landing light or pitot heat create any problems?

Most likely it is a connection problem and most likely a ground issue.

 

lee

[philiplane]

I think this model uses an electronic dimmer and not a rheostat. They are known for inducing a buzzing into the audio under some conditions. A precision ohm meter is required to verify the ground plane is correct between the affected components first, and then the dimmer must be tested if the problem persists. 

[wpbarnar]

Philiplane

You are correct.   I incorrectly used the term rheostat.  I was referring to the two rotary control switches for the panel and glare shield brightness.     I found a box in the avionics bay that I believe to be the dimmer, but not 100% sure.

I am still in the early stages of trying to comprehend how this whole system works.  A lot of different boxes with hard to trace wiring between them.

Bill

 

[Yetti]

http://www.amazon.com/gp/product/B001CM74R2/ref=pd_lpo_sbs_dp_ss_3?pf_rd_p=1944687622&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=B007V1B0W8&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=1A234K56EE4E181SVJHV