no amp? only one speaker working,no tweeter

Hey everyone, I have a 2001 Tundra and upon pulling the stock HU i see no amp . I have no dash tweeters (no grill for them) I cannot locate an amp anywhere. Do I have another hermaphrodite? seems every truck I buy is made up of parts from different years or models. the stock radio has three plug outlets but the large single one has nothing going to it and i only have a front right speaker.
2 questions....is the HU blown and which pins and how do i test them
other option is buying a JVC KD920 series and putting that in BUT what pigtail do i get if I'm not sure if i have an amp somewhere?
yes the speakers are all good
any help is appreciated .....thanx

 

Welcome from LA (Lower Alabama)! You will get a lot better response by posting your questions in the 1st Gen forum and the Audio forum. Not everyone monitors the New Intros.
https://www.tundras.com/forums/1st-gen-tundras-2000-2006.2/

https://www.tundras.com/forums/audio-video.30/

 

Welcome from NY.