Lately I am having issues with some dash items. Examples the radio doesn't always work certain switches cause other items to light up. Even the salesmen switches sometimes doesn't function. Is there a certain location to check up in the dash area for grounding. Or do I need to trace every wire. Perplexed.
I would start by checking grounds. When a switch makes the wrong item respond it is often a ground issue. On my GV the wiper switch was causing the left wiper to run but not the right, but the turn signal on the right mirror would light up. The ground lead for the right wiper motor on the back of the right mirror was not installed correctly. The motor was trying to ground through the light, causing the light to light up. Just correcting the ground fixed both.
On my '97 there is a grounding bar on the driver's side under the flip-up nacelle that covers the back of the instruments. It looks like all the grounds go back to that in a row with machine thread studs and nuts. The bar has a 1/2 to 3/4" wide woven/mesh (?) metal conductor that disappears under the dash and likely goes to a chassis ground if you can get in there and follow it.
I'd probably start with checking the cleanliness and tightness of the connections to that bar and woven/mesh conductor then follow the conductor back to it's grounding location on chassis/frame and check that.
Ours has a ground not far from the ignition solenoid and close to the steering column under the flip up dash. Quite a few wires running to it.
P