[azharj]

Sir, I am not an auto electrician. The post may be helpful. I had Windstar 2000 350K miles and still in original conditions. I sold it about 6 months back, because I retired from my job and left Kingdom of Saudi Arabia. It was marvelous comfortable and I loved and cared for it as if it was my "wife" for 19 years. It served me a lot. OK I should come to my point. It looks to me strange that you will use only when parking light is on. Will you not use it daytime? I installed myself after market Front and back camera from Aliexpress. Front camera was actuated by a front switch. Back camera was actuated by reverse gear and an additional switch on dashboard. It overrode front camera if reverse gear actuated. Wiring in the ford Windstar is from modules so as to detect a fuse bulb it both are one wire is postive and other negative but the polarity is changed when parking or brake light is actuated. I took positive and negative from reverse and put a 5 pole 12 volt relay that actuated the camera. I incorporated a 12 v 10 Amp diode also to prevent revers flow of the current. I can share the circuit.