Motorhome TV voltage question

[mossypossy]

Simple question for someone who knows about electrics

I have an Avtex tv rated 4 amps

When on standby the power supply (read from a voltmeter attached to the cable) is 12v

When turned on voltage in cable drops to 9.5v.

TV fault or battery supply/wiring issue?

This drop is enough to cause red flashy light to come on the Truma control box.

 

[st3v3]

When the tv is on, what does the voltage at the battery measure?

 

[Buckby]

Our avtex shuts down if the voltage is too low it brings a warning up on screen

 

[yorkieowl]

Just asked the other half and he says most likely a wiring/battery issue, he says check the voltage at the battery when the TV is on, that will tell you whether it's the battery or wiring, then if batt voltage is low as well, then check the voltage when batt being charged, should be 13 to 14 volts if it is then suspect the batt.

 

[mossypossy]

Just checked voltages

12v only
Standby: 12.5 at tv, 12.5 at battery
TV on: 10.2 at tv, 12.2 at battery

240v
Standby: 14.3 at tv, 13.9 at battery
TV on: 11.9 at tv, 13.0 at battery