wondering if anyone has run into this before i pull the cluster

the tach will die when lights are on, then i found its just parking lights, then i found its actually the instrument cluster lights

if u dim them all the way down tach works, as u undim the cluster the tach goes down then all the way to 0 and becomes non functional

prob low voltage on the shared bus in the cluster but figured i wud ask before i open it up and start testing it all

thanks


its a 240 not 250, 244