I have a 1985 Toyota celica GTS convertible for about two month now the head light were working fine untill a week ago..Now the head lights don't work at all..I've checked all fuses there good..Bulbs are brand new..What else can it be?..

Lots of help in the link

https://www.google.com/search?q=1985+Toyota+Celica+GTS.+The+convertible+top+won%27t+go+down

Make sure the valve is in the right position

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Test the wiring from the power source.
images for 03 Toyota Celica GTS wiring manual

91 toyota celica gts where do the two alternator connector wires opposite...

Check the breaker on the driver side kick panal under the fuse box , mounted next to the fire wall yellow and white wires 10 mm bolt remove and on the end insert small pick into the hole to reset the breaker

It sounds like you catalytic converter is clogged. You can get a universal replacement cat from Jeg's for $50.
If it is a clogged cat, it will be getting really hot.

CHANGE THE DIMMER SWITCH THE CONTROL TO CUT THE LIGHTS ON WITH

I have the same problem. Maybe it the switch unit on the steering wheel?

Double check coolant to make sure you don't have oil floating on top. It's either an exterior leak, which would mean head gasket or valve cover gasket or it's an internal leak which would also mean head gasket. It it was burning that much oil in that a time, it would run poorly and you'd most likely get a check engine light.

sounds like a clogged fuel filter to me.

Check the harness connections located inside r-rear trunk panel. You will find power top motor & wire harness there.