Numpty award claim - Eberspacher power supply cables

[superheat6k]

OK so now the colder weather is arriving I decided to test out the Eberspacher D4. This worked just fine at the sea trial, but has not been turned on since.

So I discover the thing is completely dead. Here is my fault finding and discovery trail ...

Power 12vdc +VE is present at both fuses, even with the supply isolator switch off - Odd !

I then check all the plugs on the wiring loom - all are tight.

I then notice the thick brown wire from the supply loom runs back to the port battery +VE. The same battery I changed about 2 months ago. I then realise the brown wire is in fact the -VE. I have also checked this on the Eber wiring diagram.

So this explains why I have 12v at the supply fuses. These I also checked are good.

So some numpty (ssshhh - this thread author) has connected the brown negative to the + VE.

So now I have corrected the incorrect connection the numpty (above) caused, but still nothing.

What I am struggling to understand is where the incorrect +VE supply could have flowed to - as with both the normal supply +VE and negative connected to +VE there is no circuit.

I can't see from the diagrams any other -VE connections that could have caused a reversed circuit through the controller.

I have not checked that the pump -VE routes via the heavy brown -VE, as this is the only other -VE feed on the heater. If I find this is routed separately to -VE am I likely to have toasted the controller ?

Finally I have noticed a separate fuse on the Control supply feed (5a +VE), but to access this I have to remove the 240v protective perspex covers. So if this has blown, how ?

Might have a broken D4 available for spares shortly !!!

 

[PaulRainbow]

OK so now the colder weather is arriving I decided to test out the Eberspacher D4. This worked just fine at the sea trial, but has not been turned on since.

So I discover the thing is completely dead. Here is my fault finding and discovery trail ...

Power 12vdc +VE is present at both fuses, even with the supply isolator switch off - Odd !

I then check all the plugs on the wiring loom - all are tight.

I then notice the thick brown wire from the supply loom runs back to the port battery +VE. The same battery I changed about 2 months ago. I then realise the brown wire is in fact the -VE. I have also checked this on the Eber wiring diagram.

So this explains why I have 12v at the supply fuses. These I also checked are good.

So some numpty (ssshhh - this thread author) has connected the brown negative to the + VE.

So now I have corrected the incorrect connection the numpty (above) caused, but still nothing.

What I am struggling to understand is where the incorrect +VE supply could have flowed to - as with both the normal supply +VE and negative connected to +VE there is no circuit.

I can't see from the diagrams any other -VE connections that could have caused a reversed circuit through the controller.

I have not checked that the pump -VE routes via the heavy brown -VE, as this is the only other -VE feed on the heater. If I find this is routed separately to -VE am I likely to have toasted the controller ?

Finally I have noticed a separate fuse on the Control supply feed (5a +VE), but to access this I have to remove the 240v protective perspex covers. So if this has blown, how ?

Might have a broken D4 available for spares shortly !!!

In a rush, but a quick answer to "Power 12vdc +VE is present at both fuses, even with the supply isolator switch off - Odd !"

That's the correct way to do it. The heater has to go through a shutdown sequence, turning the power off without it could mean that the heater doesn't cool down properly and that can cause a fire.

 

[TSB240]

A very quick look at a circuit diagram shows a protective diode on the heater controller board on the negative. If there has been a complete circuit then the "Numpty diode" may have blown before any damage was done. Others may know if it is easy to solder a replacement.
Replacement controllers are probably more than a new heater from the far east!

 

[superheat6k]

A very quick look at a circuit diagram shows a protective diode on the heater controller board on the negative. If there has been a complete circuit then the "Numpty diode" may have blown before any damage was done. Others may know if it is easy to solder a replacement.
Replacement controllers are probably more than a new heater from the far east!

Is this the diode - as highlighted - looks like a zener. 12 V or perhaps higher ?

Thanks.

 

[TSB240]

Is this the diode - as highlighted - looks like a zener. 12 V or perhaps higher ?

Thanks.

View attachment 145514

I think you will find this is a "sealed or potted circuit board" . You have a world of pain trying to DIY mend. I would bet your order to the Wung Hung Low corporation Ce for a new heater will be delivered before you get yours working and for a lower price.

 

[superheat6k]

I have found a CR2032 battery in the controller. I'm going to replace that and see if it comes to life. If not then its time for a new Chinese unit.