Strange earthing problem

[T1 Terry]

Help This is not the Crusader van rewire, that passed with flying colours, this is an A van motorhome.
Checking the resistance on the earth circuit from the shore connection inlet to all the power points, within spec, connect the earth from the body to the earth link busbar and the resistance goes up to 29 ohms, way outside spec, disconnect the body earth and all returns to spec .... any ideas where I should look?
It doesn't make sense to me that a connection to the body added to all the other earth connection would cause the resistance to increase?

T1 Terry

[supersparky]

It was good to have a yack T1, after you had solved your own problem.

[jon_d]

electrolysis or a dc earth loop.

Instead of measuring ohms, measure current and see what you get.

[Vik351]

Help This is not the Crusader van rewire, that passed with flying colours, this is an A van motorhome.
Checking the resistance on the earth circuit from the shore connection inlet to all the power points, within spec, connect the earth from the body to the earth link busbar and the resistance goes up to 29 ohms, way outside spec, disconnect the body earth and all returns to spec .... any ideas where I should look?
It doesn't make sense to me that a connection to the body added to all the other earth connection would cause the resistance to increase?

T1 Terry

A mate has a A van fold up job ,any use talkin to hum ...???

vik...???

[T1 Terry]

Turned out to be the control circuitry on the water heater. When I unplugged the water heater, the problem went away. Then Sparkie Dave gave me a call and shone some light on the possible cause. Capacitors in the control unit charging with a drain resistor linked to the heater body is one possible cause, the other is back feed from the body earth to the battery negative and doing a loop through the negative in the inverter to the earth circuit.

Anyway, problem solved and many thank to Sparkie Dave for the phone call and all who offered help, aren't these forums great

T1 Terry