Hello and welcome to the forum Chris - I'm guessing that you're already signed up on our Pelican Part forum from your various Porsches. This community is just as knowledgeable and helpful; so please feel free to post any inquiries. As with our Porsches, we have a vast DIY tech article section - I'm attaching the W126 one for you. Welcome!

https://www.pelicanparts.com/techarticles/MBZ_Tech_Index-W126.htm