So I have about 0.5 to 1V cooltage drop between the fridge freezer and heating display which are both at the same distance from the battery bank.
All connections are ok but as soon as i turn the heating on I often end up with a 00
The workaround is to run the engine while the parking heater heats up
Now i am unsure where the drop is caused between the battery and heater or that the detection is simply wrong by the control unit.
Has anyone any experiencing in upgrading the cable to a different AWG…and if so will the battery to heater suffice (I presume the power to the glowplug is relay controlled) or would i need to upgrade the wiring to the control unit as well
The most important thing here is to check all of the supply wiring connections to make sure they are all sound.
It sounds like your issue is that there is enough voltage drop to prevent the heater from starting up on just battery energy alone because of a bad connection somewhere and that there is enough voltage to run it once it has warmed up!?!
My guess is that once you start the engine, the charging voltage is enough to overcome the voltage drop you have when you start the heater up!?!
Any dry connections will cause a voltage drop and this is one of the main reasons that these heaters fail!
I had an experience recently where my heater was showing only 3 volts. It turned out that the crimp connector I used to extend the ground wire had become loose and the wire ends had become oxidised…the solution was to re strip the wires so I could see clean copper and then crimp another connector on to the wire ends and then everything was fine.
This simple solution saved me the heartache of a new control unit or motherboard!
I hope this helps!