My sunpro tachometer II stoped working in the Dart, worked ok then stoped & stuck some time wall driving at 2000rpm,got back home, taped side of tach, went to back to 0, but can't get back working, sanded ground under dash, red wire seems connected ok & fuse its on is good, coil connection seem good.
Is ther anything inside the tach that can be fixed?

Back (way back) in my day a Sun tach was the ultimate tach to have. I still have a Sun 502 that is still working after 51 years. However, Sun was bought by Actron (Cleveland, OH, 800-228-7667) and produced the Sunpro line. Sometime recently Actron was bought by Bosch. I don't know where they are made these days but I could probably guess. At their price range I'm sure they are considered "throw away". If you've got to have that traditional Sun SST look your choices are few. Another Sunpro or a real Sun tach (Ebay and $$$). Autometer has a line of traditional style tachs. Over the years I've had several Autometer tachs in several cars and had to send a couple back for repair but Autometer's customer service and repair are excellent and very reasonable.

yep, pretty much a throw away http://www.summitracing.com/parts/sun-cp7903/overview/

The Sunpro befour this one was better, it lasted 8yrs or longer, it was in the car when I got it 12yrs ago, I'll prob. get me a new or used sunpro to go back in, just don't seem right with out a super tach II.

As you've done; confirming the red is hot the black is grounded and the green has continuity to the coil pri neg, you could open it up & see if you see any loose wires/connections but since it'd likely be all electronic in there about all a person can do is send it in

I was curious so I did some more looking and found tons of useless information. I was right about where they were made.
"Since the 1980's, Actron has used acquisitions to advance its market position with significant additions: In 1986, Actron acquired the KAL Equip Company, a maker of professional automotive diagnostic equipment. And in 1988, Actron licensed the rights to the Sunpro tachometer and gauge business from Sun Electric/Snap-On.
Meanwhile the company was years ahead of all other industry players with the implementation of its "right-sourcing" manufacturing strategy and the establishment of a factory in Yantai, China, in 1989."
I also found out, while there is still a huge inventory of Sunpro tachs, they now say Bosch and have changed the face slightly. Right now Summit still has Sunpro online for $40 but Jegs does not. Saw one new on Ebay for $29.99/free shipping. Of course, most of your chain auto parts stores still advertize Sunpro gauges.

if you click on my link sunpro at summit for $29.50

Yep, but mine is the black & chrome one $39.97, so far summit seems to have the best price, looked at some on ebay with better price. but just don't know about their feed back!

amazon have it for $34.99, spend another cent and get free shipping lol

I have the old style with sending unit a good tach the Sunpro I have is a paperweight