Yeah, thats the potentiometer. My advice, until you get it fine tuned don't reconnect the speedo, its a real PIA, plug in the inner white plug only. Start the truck, see where its at, and adjust as necessary. I pulled mine probably 10 times before I got the adjustment just right. Don't feel bad though, I learned the same exact way after installing my full guage cluster. :cheers:
so what should the renix 4.0 be ideling at?