Driving my 94 E320 last night after dark on the interstate. Traffic moving about 60mph, outside temp about 85F, coolant temp gauge at about 90C, everything seems fine except the coolant temp idiot light is faintly glowing. Drive home turn engine off, check coolant level everything is OK. No leaks last night, none this morning. Drive to work in bright sun, can't see the light, pull into the parking garage and see the light dimly illuninated. Any ideas?
regards,
Mark