Headlights pulsing/flickering
Have led lights in my 91and did not affect the operation nor flickered. Also had them on my previous 85 after HID without issues, the lights are fed via relays so will not be affected. What year is your C4?, I know my 85 I could keep the lights from flipping down by not pushing the switch fully down. Was handy as would prevent hot HID globes from failing that sudden thump closed when hot, however the Led globes didn't get affected by the sudden jolt. Check your headlight motor wiring plug is connected and not corroded, you could be having motor issues developing. They are quite fragile, if still using the original gears and bushes.
Have led lights in my 91and did not affect the operation nor flickered. Also had them on my previous 85 after HID without issues, the lights are fed via relays so will not be affected. What year is your C4?, I know my 85 I could keep the lights from flipping down by not pushing the switch fully down. Was handy as would prevent hot HID globes from failing that sudden thump closed when hot, however the Led globes didn't get affected by the sudden jolt. Check your headlight motor wiring plug is connected and not corroded, you could be having motor issues developing. They are quite fragile, if still using the original gears and bushes.
Should be same with your 90, you can get canbus decoders a resistor device. They came with my led lights however I did not need to use them, some modern cars do require these for resistance or shows
a light fault on dash.








