Battery voltage

[marantz]

battery voltage drops off when both monitor and rear camera plugged in..ok when one of them is connected.Any help please..Thanks

[Micro]

battery voltage measured where? At the battery, or the back of the monitor? How have you run your power wires?

[marantz]

Power runs from the 12  volt socket and measured there.Thanks

 

[Micro]

If you plug both in and you get a big drop in voltage i'd be concerned you have a short somewhere - do both things work when both plugged in separately or together? Have you swapped a ground/live feed somewhere?

[marantz]

Each works on its own?..and voltage is about 12 volts..when both connected I get about 6 volts..weird..can’t find any shorts as I have metered each to ground with no problems.

Edited November 5, 2017 by marantz

[Micro]

When you say camera and monitor, have you got a separate monitor and camera, or are you attaching to the stock head unit? Does the monitor work by itself (turn on, etc). Does the camera work with a different display (small lcd you can bring to the car, or remove the camera and take in the house)?

The only cause for voltage dropping whilst stuff is plugged in, is a high current draw over what the battery, and the wiring, can support. (Voltage = Current x Resistance).

[marantz]

Yes both separate and not connected to the head unit.Have also tried each with regulated power supply in the house.Cant figure this out.

[Micro]

How is everything wired power wise?

Cig socket -> Camera -> Monitor?

or 

Cig socket -> Camera

Cig socket -> Monitor

 

[marantz]

Cig socket -> Camera

Cig socket -> Monitor

[Micro]

7 hours ago, marantz said:

Cig socket -> Camera

Cig socket -> Monitor

Do the camera and monitor work as expected when both plugged in?

Where EXACTLY are you measuring the voltage? Exactly where your probes are (multimeter), or what you are using to measure the voltage?

My thoughts are:-

• With 6 volts of voltage drop, are you measuring incorrectly - if not:
• Connecting monitor and camera you are dropping 6 volts across something, and that something is likely to get hot and potentially catch fire.
• If the above is true, why are you not blowing a fuse (the supply wire to your devices is correctly fused for the amount of current that can safely flow through the wire?)

What camera and monitor setup are you using (links to products useful)? Did they both work in the house when tried?

[marantz]

With over 25 years in the electronics service this has me stumped..have removed it from the car and sent it back.Thanks