93 DL240 has oil and bat lights on with keys out of ignition

[SR Heer]

I have a weird 93 - DL 240 wagon problem - in that with the keys out and ign off the oil and sometiems battery warning lights remain on ??? but when starting and running warning lights go off - I am wondering if anyone else has had this problem and what it might be and how to check one thing or another - I was thinking it might be the ignition switch and or it might be the ECU or possibly even a relay but have no idea where to start - thanks for any ideas or suggestions!