Hello, new member here. my BIL just purchased an 80 Z28 and the tach is inop. I removed the cluster to replace the bulbs and checked the circuit board which is ok. the tach signal wire is hooked up and running through what I`ve been told is a "tach filter"? could these go bad giving no signal? it moves slightly when starting and slowly climbs when revving the motor, it just inches up. if it is the tach filter are they available from Chevy or an auto patrs store? any help would be appreciated. I`ve checked everywhere for a tach but they don`t seem to offer any new ones. we`de like to keep the factory tach to keep it original looking. otherwise I`m going to have to make an Autometer in dash tach fit nicely. I don`t usually work on these things, I stick to Fords and Mopars, but like I said it`s my BIL so I gotta do what I gotta do!

One other question. it`s an 80 Z28 without factory A/C. this doesn`t seem to be very common from what I have seen. will an A/C temp control work in place of the non A/C control? from the looks of them I say no, but I just want to be sure. eventually he wants to put in factory A/C, so yes everything else will have to be replaced!

Thanks in advance!