What is the other terminal for
 

I THINK the other terminal is for an external ground wire, though the good Dr. Porsche never included a wire to that location (I'm presuming that he presumed that the sender mounting point was a good enough ground by itself). It may come in especially handy for folks that have their sender mounted directly to their "rubber mounted" IC. Put an ohm meter between it and where the sender mounts and see if you get continuity.

That makes perfect sense now that you mention it. I was kinda hoping I could attach a second boost gauge to it....one that that went to 2 bar. Rats

Thanks to this wonderful forum, I diagnosed and fixed my boost guage brown wire in 15 minutes!

If we ever lose this forum, an awful lot of valuable info will go with it.

^^^

That is an understatement Mark!

I read and use this forum all the time and it has helped me and many of my friends solve many issues that had us stumped.

Rahl