I have a 99 TL with 235k, no engine or tranny issues of any kind. BUT, has developed an issue where intermittently while driving, all of the dummy lights on the dash will flash on and off and get brighter at the same tempo as the blower motor will speed up and slow down, leading me to believe there is obviously some type of voltage issue going on. The headlights will also get brighter at the same time as the dash lights flash. Eventually the brights quit working, but the regular headlights still work normally with the exception of getting brighter with the dash lights. O'Reilly auto parts cheapo electrical diagnostic shows no charging system problems, and OBD2 only shows an EGR and an EVAP code. I am not opposed to buying another TL with a lunched tranny to steal parts from, if it is a BCM, or full computer or whatever. Any suggestions or directions would be much appreciated.

 

Don't bother buying parts or anything until you diagnose the issue. You can get an electrical troubleshooting manual, and find the circuit that has the lights and blower motor. Or pay a mechanic to diagnose it for you.