MKIII Headlight Problem

[Supra275]

Newbie to the forum. I have a 1989 MKIII 3 litre Turbo Supra with what appears to be an unusual fault with the headlights. With the main light control in the OFF position, the engine running, headlight selection to low beam and the transmission in D the headlights intermittently light ( they do not pop up ). When driven forward the lights flicker and when stationary will remain ON until the transmission is disengaged from D ( this flickering eventually burns out the headlight relay). Immediately reengaging D will not bring the headlights on until the car moves forward. Sometimes the headlights remain on when the vehicle is parked ( key removed from ignition ). As far as I can tell it is not any of the following: faulty headlight relay, faulty / lose wiring associated with the lighting control switch, faulty relay / fuse box wiring. I am beginning to suspect a faulty retract control relay. Has anyone experience a fault like this or have some other suggestions as to what the fault could be. Thanks.

I have a few more details about the fault.

I removed the headlight relay and connected a LED indicator in its place which allowed me to see what was occurring across the relay coil.

• With the engine running vehicle stationary and in either P,R,N,D,P2 or L with the main light control switch OFF and either HIGH or LOW beam selected the headlight relay is OFF.

• Select either R, D, P2 or L whilst remaining stationary the headlight relay is OFF

• Drive the car in either of the above and the relay goes on and off at a rate that is dependent on the speed of the vehicle ( only tried this up to 5 mph ). Interestingly if you stop when the relay is ON it will remain ON until either N or P is selected. Reselecting any of the other positions after this will not switch the relay on until the car is moved and starts to go on and off again.

• Another little quirk to this problem is that with the ignition ON, engine not running and the main lights switch OFF selecting HIGH beam switches on the main beam headlights and the blue main beam indicator on the dashboard. This does not happen when dipped is selected.

In all of the above the headlights remain in the retracted position. Also the O/D light flashes when the O/D is selected – I believe this to be a gearbox setup problem and is not associated with this one.

Thanks.