Eberspacher D4 stopped and blowng 20Amp fuse.

Momac

Momac

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Eberspacher D4 had been run some hours yesterday. Suddenly the heater stopped at about 8pm . A whisp of smoke from the exhaust . So I switched it off .
This morning found there are two fuses . The 20Amp fuse had blown.
Fitted a new fuse just now and it has blown immediately. This is with the heater controller switched off.
What should I investigate next?
 
MartynG said:
Eberspacher D4 had been run some hours yesterday. Suddenly the heater stopped at about 8pm . A whisp of smoke from the exhaust . So I switched it off .
This morning found there are two fuses . The 20Amp fuse had blown.
Fitted a new fuse just now and it has blown immediately. This is with the heater controller switched off.
What should I investigate next?
Click to expand...

I know where you can get a very good replacement for £130 delivered with better controls
 
I would like to understand what has gone wrong.
I am thinking the hours run on a low setting may have caused carbon to deposit but not sure why this might cause a short circuit. Maybe the glow pin has failed? Would glow pin failure explain why the 20 Amp fuse has blown and the new fuse blows immediately? If so a new glow pin appears to be a £40 part ... or less .
 
MartynG said:
I would like to understand what has gone wrong.
I am thinking the hours run on a low setting may have caused carbon to deposit but not sure why this might cause a short circuit. Maybe the glow pin has failed? Would glow pin failure explain why the 20 Amp fuse has blown and the new fuse blows immediately? If so a new glow pin appears to be a £40 part ... or less .
Click to expand...

Yes it would. The only thing that draws any significant power on these things is the glow plug. I suspect yours has failed and is shorting out. I would replace it.

You could test it with a multimeter to see if it has shorted and if so take out the old one compare it with one on here. Or just replace it anyway they look cheap enough

https://www.ebay.co.uk/sch/i.html?_...S0&_nkw=glow+plug+for+Eberspacher+D4&_sacat=0

Dennis
 
Or just disconnect the glow pin and replace the fuse. No blow = dead glow pin.

Although that wouldn’t explain the failure whilst running, as the pin is only used at start up.

Possibly seized fan motor, but that wouldn’t explain the fuse blowing with the heater off.

Check those two first, then if no go, disconnect the heater from the loom (and disconnect the control box plugs too). Replace fuse.

Blow = wiring loom short, no blow = bigger problems.....
 
I disconnected the multi pin plug from the heater. Put in new fuse and it had not blown.
I have no idea how to disconnect the fan or the glow pin individually to test.
Perhaps next step is to remove the heater.
 
Ok, not intimately familiar with the D4, but almost every heater has a cover over the glow plug as it’s a maintenance item. You need to find this, remove it and disconnect the glow pin next. Plug the heater back in with the glow pin disconnected and report back :)
 
rosssavage said:
Ok, not intimately familiar with the D4, but almost every heater has a cover over the glow plug as it’s a maintenance item. You need to find this, remove it and disconnect the glow pin next. Plug the heater back in with the glow pin disconnected and report back :)
Click to expand...

If you get that far I would just put in a new glow plug given they are quite cheap
 
Last edited:
rosssavage said:
https://www.butlertechnik.com/downloads/Airtronic_D2_D4_workshop_manual_2.pdf

Page 29, item 9. Has a plug on it, pull that (assuming D4 airtronic)

Page 31 shows you how to do it.
Click to expand...


Thank you. I now see now where the glow plug is and how it can be disconnected.

I have removed the heater unit and now have it at home. Would prefer to repair the heater rather than buy a new one.


The fan turns freely by hand so does not appear to be seized. Still not certain if the fan or the glow pin are the fault.
Now I am slowly beginning to understand how it all works . It may take me a while to sort out.
 
MartynG said:
Thank you. I now see now where the glow plug is and how it can be disconnected.

I have removed the heater unit and now have it at home. Would prefer to repair the heater rather than buy a new one.


The fan turns freely by hand so does not appear to be seized. Still not certain if the fan or the glow pin are the fault.
Now I am slowly beginning to understand how it all works . It may take me a while to sort out.
Click to expand...

That is the beauty of doing it yourself you learn loads rather than just throwing money at a problem
 
If you do end up replacing the plug, replace item 10 at the same time (screen) These get full of burnt on carbon and can cause further issues.

You’ll probably end up destroying it on removal. Use needle nosed pliers, and it WILL be stuck in there!!

They need a special tool on reassembly, but would you believe Eberspacher supply that tool FOC with the new screen. :)
 
artisan said:
On the Sealine forum there is a how to on the replacement of servicable parts. I believe you can buy a service pack from an Ebby dealer which would include the glow plug, filters etc.

here it is

http://sealineforum.co.uk/t2716-eberspacher-d4-clean-and-strip
Click to expand...

Thank you - that looks very useful .

I don't expect to get any further until the weekend as my work life balance is not right . It's interesting to see the glow pin can be removed using an ordinary spanner after the fan is removed.
 
After disconnecting the fan and the glow pin electrics I refitted the fuse. Some smoke from the ECU area prompted me to pull the fuse.
After that the fuse does not blow. I have reassembled the heater and switched it on. The red and green LEDs are lit but no activity from the heater. The fuse had not blown.
I am now thinking it's an ECU fault?
 
May be easier to replace it with a Chinese diesel heater about £120 you already have the ducting in place and they are
a copy of the eberspacher this is what I did when mine packed up.
 
peteK said:
May be easier to replace it with a Chinese diesel heater about £120 you already have the ducting in place and they are
a copy of the eberspacher this is what I did when mine packed up.
Click to expand...
The existing heater is 16 years old so I am not complaining. But I don't want to make the mistake of buying the wrong part .
Replacing the ECU is easy.
 
I replaced the ECU today.
Quite relieved everything is working as it should. I allowed the heater to run for half an hour on full power before switching it off.
 
I bought the ECU from kirknalls.co.uk
It took a few days to arrive by snail mail but otherwise no issues.
 
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