I3,

Its not important how long the dash GP light stays on, its important how long the GP relay turns the GP on. The dash GP light does not indicate that the GP are are energized. It is just an indication how long to wait to start engine and it can be out of calibration, I.E. not telling you to wait long enough.

How did you check the GP?

Do a search on Cabin light and follow the directions there.

P E H