This message is for 92 Silverado I know this is six years after your discussion about the Technics equalizer din plugs, but I have been searching for a Technics car stereo equalizer for 25 years now. I have one that I bought 30 years but it's been fried for the last 25 years and I've been trying to fix it. I can't believe you managed to find one for 10 bucks. anyhow, it sounds like you might have the Technics cyEQ 14 or maybe the EQ 10 I have the EQ 14 do you still have it.
if so I will pay.$$$