Recently installed back up camera has a bright display in day light and only 50% or less at night. I at first blamed the camera. I have now removed the brightness of the tag lights as the cause. I have been able to determine that the camera display is very bright at night as long as the dash light switch is off. When I turn the light switch from "off" to "accessory", the camera display dims. There is no affect when I turn it father to head lights. My first thought was that the tail lights were drawing so much current that it was causing the back up camera to dim.However according to my owners manual ( 2004 model), the back up lights that are sending power to the camera are NOT on the same circuit as the park/tail lights. My backup lights are on #20 circuit which powers the camera) and the park lamps and license plate lamps are on #31.The radio ( with display screen) is on it's own circuit.

The following are listed as on the circuit with backup lights:
Ant-lock brake system (ABS) module
Brake-shift interlock
Speed control module
Overdrive cancel switch
Electronic flasher (turn/hazard)

Any ideas as to cause of the dim display appreciated.

 

Did you hook up the display to the instrument lights?

Radios displays do the same thing when you turn on the light switch they dim to whatever the dimmer wheel is set to

 

I did not make a change to the old wiring. I received two wire kits with the radio--one that fit the radio and 2nd to connect old Ranger wiring to new radio wiring. I was careful connecting it all and connected by function not wire colors. I checked also the dimmer wheel and radio. The wheel adjustment has no affect on the brightness of the radio screen. Today, I removed the back up light bulb and the tail light bulb. This did not change the dimming problem.. Since the back up lights are on the 10 amp circuit with the over drive switch, I even turned it on and off with no change in display..

As a last resort I could try a 18 ga. wire from the battery to a relay at the rear backup light and allow the relay to connect the battery current to the camera.when the back up light comes on. My camera wiring is such that when the camera is powered, it also triggers the radio to change to camera screen. Not sure how to wire that relay as yet.

Any other things I can check?

 

Try the camera at night but in a well lit area maybe the automatic iris in the camera is not working so dimness is because there is not enough light for the camera with smaller iris opening

Camera doesn't "know" day from night unless its hooked to light switch, i.e. dimmer wheel
If it doesn't have an auto iris then image will be dimer as light gets less and less

 

Problem solved. I have never had the new radio on at night. here is the info from a web site: "In short, the illumination wire on a car stereo wiring harness is used to dim the screen on your aftermarket car stereo. The wire is connected directly to your instrument cluster and provides a negative trigger or positive trigger that tells your radio when you turn on and off your headlights. On mine, it's "any" lights"

I just turned on my radio ( mid day) and then turned on park lams. Radio screen dimmed. I did not change the old wire harness so I guess the old radio had the same function. Looks like the only solution is to snip the illumination wire and determine if radio is too bright at night.

Good news is that there may be others wondering about the same issue.

 

Glad you got it solved

Good work