Wiring Harness Needed

What surprises me as a former radio maintenance technician then a
systems engineer is that they would change the wiring harness at all.Â*
All two way comm radios require the same basis signals:Â* Vcc, Gnd, Ptt,
Audio, Mic, and their associated grounds.Â* The factory already has the
jigs for building harnesses.Â* Why change all of that simply because a
new feature has been added?Â* Simply add another wire in a different pin
location.

Oh, I get it.Â* Someone else designed the new radio and had to make his
mark by changing the wiring harness.Â* Just like on my car electronics.Â*
It appears that at least four different individuals had a hand in
designing user interfaces for the different screen functions so all of
the buttons are in different locations.Â* Junk!

On 9/6/2019 4:34 AM, James Thomson wrote:
At 09:24 06 September 2019, Surge wrote:

It looks like the wiring harnesses are fairly standardised with only the
connector type and pin order being different.

The devil is in the detail! The connector may actually be the same but
which wire to which pin, whether wires are linked, and what is earthed may

be critically different. At least one radio manufacturer offers adaptors

boards to let you link your existing harness to his new generation 8.33
radios.


--
Dan, 5J

I’ve purchased three harnesses over the last few years. One made by Goddard was by far the nicest unless you try and get an original factory replacement.
The factory replacement harnesses for these older radios aren’t readily available, so you might end up with a newer model radio harness and have to
dead end a number of wires in the harness for functions the older radio doesn’t have.
The Goddard harness I purchased was well made, Tefvel wiring, each wire and function labeled, appropriate ends on the wiring for shielding, etc. it’s the only way to go as far as I’m concerned, especially with an older but quite functional radio!
And I’m sure any of the soaring supply distributors would appreciate it as well.
Regards, Mark

On Friday, September 6, 2019 at 8:16:50 AM UTC-7, wrote:
I’ve purchased three harnesses over the last few years. One made by Goddard was by far the nicest unless you try and get an original factory replacement.
The factory replacement harnesses for these older radios aren’t readily available, so you might end up with a newer model radio harness and have to
dead end a number of wires in the harness for functions the older radio doesn’t have.
The Goddard harness I purchased was well made, Tefvel wiring, each wire and function labeled, appropriate ends on the wiring for shielding, etc. it’s the only way to go as far as I’m concerned, especially with an older but quite functional radio!
And I’m sure any of the soaring supply distributors would appreciate it as well.
Regards, Mark

For 90% of pilots, that's the way to go: Buy a harness for the new radio.
And for those thinking about upgrades, the stuff from 30 years ago may not be compatible with new models but some intermediate models may have the same wiring.
I've recently replaced a FSG-71M with an FSG-2T... Plug and Play.
Also replaced an AR4201 with an AR6201... Plug and Play.
Removed another FSG-2T, replaced with XCOM, a bit of work and a microphone change.
Later replaced the XCOM with a TY91. Ordered a harness with the TY91.
Consider the compatibility of microphones in the upgrade. Some radios do not have inputs or preamps for different microphone types. One reason for changes to the wiring harness of newer radios.
The newer ones may have auxiliary audio inputs. Some have separate microphone and PTT connections for each seat. More attention may have been paid to grounding schemes.
There are different pin counts and locking types for D-Sub connectors.
Pretty much replacing anything that doesn't fit in a 57mm cutout is going to take some work. But it'll be worth it!
Jim