The headlights have a systematic low intensity flashing issue. It stops if I engage high beams. Voltage jumps when tested. Noise coming from under dash, relay?, that is in time with flash. Checked switch OK. I manually hit relay mount assy and headlights go out completely and noise stops. I want to change relay but cannot reach it on top. How do iget relay mount assy out to swap relay? HELP! Driving me crazy.

 

on several Volvo models the low beam relays are embedded in the CEM - which as it happens is under the dash. High beams route separately so I'd suspect your CEM. Check to see if your year is a simple swap out or if its paired to the ECU (on my 2000 S40, it was a simple swap out...)