Citreon Picasso headlamp indicator fault dash dims when right indicator operated and turns off?

The issue with the Citroen Picasso headlamp indicator dimming and turning off when the right indicator is activated may indicate a problem with the electrical system, such as a faulty relay, a short circuit, or a wiring issue. It could also be related to the bulb itself or a poor ground connection. Checking the wiring harness and connections for any signs of wear or damage is advisable. If the problem persists, consulting a professional mechanic for further diagnosis would be recommended.