Jump to content

monster electrical gremlins


podair

Recommended Posts

Hi, electrical gremlins are back!
I am trying to troubleshoot my alternator problem and would be grateful for your collective wisdom...
I fly a 1967 Mooney M20F with a Plane Power alternator conversion. The alternator is under two years old , the regulator (Plane Power) is ten years old. Over the last few flights I get increasingly loud static in the intercom and radios to the point I have to pull the Alternator Field breaker to use the radio as the static is very loud, and then only push it back in when volts on the EDM 700 drop under 12.2 volts. Only pulling the alt field breaker kills the noise. On the ground it goes away and only reappears above 2000rpm
I have tried every combo possible, pulling every breaker or switching off any electrical device, taking every USB charger out etc etc. What seems to happen is when the alternator is done charging the battery (amps drop to about +2) the noise increases continuously. If I add some load, ie switching on pitot heat or strobes the noise goes away a bit and then comes back after a while. Even when the radios are switched off, the noise goes through the intercom. It is heard at first on my new 8.33 trig radio and then on the older king and then everywhere!
Every time I push the field breaker in, the voltage goes up to 14.1v as it should and the output is 20/30 amps, progressively reducing, and then the static comes back. 
I have checked grounds as far as I can but maybe there is a bad ground somewhere. The alternator seems to be OK as everytime it comes online and the output is OK, but could it be a diode?
As it is clearly output driven, I think it is the regulator, any other views?

Link to comment
Share on other sites

Be cautious disengaging and more importantly re engaging the alternator. 

I suggest turning off your avionics prior to popping the breaker back in, then turning the avionics back on.   

I had both of my comms - a 430 and a KX-155 go dark on me and it cost north of 4K to make em light up again.   According to the avionics repair shop - they were subjected to a power spike when I did something similar.  

Link to comment
Share on other sites

Be cautious disengaging and more importantly re engaging the alternator. 
I suggest turning off your avionics prior to popping the breaker back in, then turning the avionics back on.   
I had both of my comms - a 430 and a KX-155 go dark on me and it cost north of 4K to make em light up again.   According to the avionics repair shop - they were subjected to a power spike when I did something similar.  

Is your 430 a dual voltage type?
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.