Stop in for a cup of coffee

Back from test drive... The lights only come up after it sits a long time, mainly overnight. Restart it and they clear. They do not come on while driving.
Interesting. Would need to know what the trouble codes are. Now what comes to mind is low voltage during crank after sitting. Borderline weak battery or a parasitic draw. My avalanche has a parasitic draw i have yet to find. And abs gets goofy if i start it when battery is low. Restart after a minute or two and fault clears.