Time to replace my AV relay in the 252.

[shawnd]

Here's the Mooney instructions (scanned using iphone, sorry for the quality):

INSTRUCTIONS.pdf

EFFECTIVITY.pdf

RADIO MASTER.pdf

[Yetti]

On 1/13/2024 at 9:41 PM, Aerodon said:

Shawn,

The way the avionics relay is wired up, if you inadvertently try to start while the avionics are on, the starter switch should also turn the avionics off.

I looked at my CB panel assembly again, it would appear that I do not have the original avionics relay, I can see where this relay was removed and replaced by the 100A solenoid (as shown here), probably as per the service bulletin kit you have received.

Aerodon

 

 

 

 

 

In the older models  ie 75 F   The avonics switch Turns the relay off when energized.  ie applies power to the relay which uses opens the NC circuit.   This is the fail safe if the relay fails, the avionics will still stay powered.    The key switch to starter solenoid positive wire also goes to the avionics relay and applies power, which kills the avionics by opening the NC relay.

[Aerodon]

I have a spare 28V 100A Kissling relay if anyone else wants to do this upgrade....

Aerodon

[joelskousen]

My 1987  M20K 252 has just developed the same problem---avionics won't shut off with the toggle switch (no rocker switch on this a/c).  The discussion so far has been very helpful, but need more info on getting to the control relay and the controlled relay.  Can only get the CB panel rack out about 5" with all the mass of wiring attached to the CBs.   Any tips on how to get access to these relays to replace or repair? 

Also, a few of you seem to indicate there is a replacement solenoid for this dual relay setup, but none of the links or pictures are active in this thread.  Any help would be appreciated. 

[shawnd]

My local avionics shop tagged and disconnected the connectors on the back to be able to slide the tray out.

Hmm all the pictures are showing up correctly for me. They are hosted on this forum so the if you can get access to the post - you should be able to get access to the photos. Here's my post with a photo of the solenoid:

 

 

[Aerodon]

On 3/9/2024 at 4:17 PM, joelskousen said:

My 1987  M20K 252 has just developed the same problem---avionics won't shut off with the toggle switch (no rocker switch on this a/c).  The discussion so far has been very helpful, but need more info on getting to the control relay and the controlled relay.  Can only get the CB panel rack out about 5" with all the mass of wiring attached to the CBs.   Any tips on how to get access to these relays to replace or repair? 

Also, a few of you seem to indicate there is a replacement solenoid for this dual relay setup, but none of the links or pictures are active in this thread.  Any help would be appreciated. 

If you've already taken all the screws holding the whole panel in, and disconnected the 2 or 3 connectors, the wires that are likely holding it are the 2 alternator wires and main battery wire.  I took these off the circuit breakers.  There might have been one or two more wires (cigar lighter?).  

Aerodon