Hey guys so i have a 85 camaro which i had installed a 2" tach but decided to replace it with a 5" tach that i had in my other camaro. So after i installed the new tach it worked fine for about 2 days then it started acting up. Now majority of the time it sits a 0 and sometimes it will bounce to 1k then when i accelerate it will work but still bounce around. At first i thought it was the wiring so i ran all new wiring for it but that didnt fix it. So then i decided to install my other 2" tach again and it worked just fine...

Can anyone tell me what the issue could be??? Bad tach?

Also i want to mention that the new 5" tach is set up for a v8 and mine is currently a v6 but to my knowledge that would only make it read the rpms wrong, not make it jump around and not work majority of the time.

Please let me know what you guys think the problem is. Should i buy a new tach or is there something i can to to make this one work?