 If they go dimmer, dimmer, that tells us that the starter motor is trying to engage, but it can't for some reason, an internal failure perhaps. Maybe the engine seized. I mean, I don't think so, but hey, anything's possible. If the headlights don't change, that means the starter's not doing anything. Why isn't it doing anything? Again, it could still be a starter. Does the starter have a good connection at the solenoid? Is it making all proper connections?