This is a PI filter I built to correct noise in the audio system after I installed two LED landing lights on my RV-4. I used a small piece of fiberglass for a circuit board. You will have to build one for each light and mount it as close to the light as practical. The lights I used ( see below ) only required 1 amp so the inductor I used is rated up to 1.6 amp. If your light requires more current then you will need to use an inductor with a higher rating. I purchased the components from Digikey.com. I used a post on Vansairforce by Dean Wilkinson as the genesis for this.
Item Qty P/N Desc cost each
C1 & C2 2 445-173261-1-ND CAP CER 1UF 25V X7R RADIAL $0.32
C3 1 1189-1583-1-ND CAP ALUM 1000UF 20% 25V RADIAL $0.64
L1 1 732-4206-ND FIXED IND 100UH 1.6A 190 MOHM TH $2.46