Can one of you electronic folks tell me what (inline) devise would be needed that would allow a 12 volt light to remain on for a few seconds then turn off.

Doing an external voltage regulator conversion on a 95 Jeep Wrangler which will result in the check engine light staying on - because the ECM contains the OEM voltage regulator. It's a yard vehicle and I like seeing the dash lights so I know the key is in the on position. I assume the light is analog.