'94 Trooper Problems

So occasionally the voltage on the dash spikes up to 16 and when that happens all the warning lights go beserk. Check Trans, Battery, Engine are the big ones. My dad heard from a friend that sometimes the voltage misread is caused by a shortage in the spark plug wires so we changed those and it seemed to be fine. However a few weeks later the lights would briefly flash at varied but rather short intervals. Does anyone have any advice on what else might be bugging the Trooper?

16? Is that a volt meter of sorts?
If so, it really shouldn’t exceed 14.5 under normal conditions. Is that where it seems to be when it all works well?

If so, it could be the voltage regulator. Not sure on your trooper but it is very often located inside your alternator, needing it to be replaced. Before you start swapping more parts, I’d check all your grounds. Make sure they are clean and tightened properly.