Asalam o alaiqum,
As per the title, I get a significant drop of 300 RPM when I turn on the headlights and the RPM comes to down to 500-450. In day times when there's no need of lights RPM stays and 800-750. Other than that whenever I stop at signals or with idle car but in start position headlamps and dashboard lights go dim and backups up when the accelerator is being pressed.
Engine specs are: 4E Toyota engine
Car: Toyota AE90
Radiator Fan: Direct connection.
What I want to ask is this because of some faulty sensor or its just normal? Moreover I also need genuine wiring of 4E Toyota engine with engine check light capability.