Often the dash dimmer won't play well w/ LED. Move dimmer knob full on. Or bypass the transistor.
See my Cave, Dash Dimmer
Should not install LED to replace warning lights.
More so w/ bat/alt light that needs proper bulb resistance to make the alt to work.
Sockets and dash "board" can be iffy not getting good connection and LED just make that more obvious.
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
The Ogre's Fiero Cave