Finally got my 1981 running. Trying to figure out why the temp and fuel gauges aren't working. They're both maxed out, meaning i have an open. Since i know both senders are plugged in, i presume i am looking for a common ground at the dash. Before i pull the cluster back apart, has anyone run into this before? Assuming i have the connections secure at both gauges, is there a common ground back there i missed? I don't have my AIM on me, so I'm just reaching out for thoughts before i get back into it.