There are "load adjusters" to stop the "hyper-flash" when LED bulbs replace the normal bulbs in the turn signal positions. They have to be grounded to the body, I believe. They are available many places.
The other issue which affects instrument cluster bulbs is accumulated ingress of fine dust that gets into the interior. Lowered windows and such. Just a cleaning out of the cluster and the "filters" for the bulbs can make a good difference in the resultant brightness of the bulbs. Like getting a better reflector. Not unlike cleaning out a tail light housing and lens.
The other issue which affects instrument cluster bulbs is accumulated ingress of fine dust that gets into the interior. Lowered windows and such. Just a cleaning out of the cluster and the "filters" for the bulbs can make a good difference in the resultant brightness of the bulbs. Like getting a better reflector. Not unlike cleaning out a tail light housing and lens.
