1999 Dodge Caravan eletrical - possible computer

1999 dodge caravan starts and runs fine but service engine and yellow brake warning lights stay on. No guages or dash lites. Turn signals, head and tail lites ok. No speedo. Have checked fuses but did not find problem. Tried swithing relay around but did not seem to make any difference. Heater blower a/c seem to be ok. Not sure if abs is working but brakes seem ok.