Eberspacher ecu

[Bojangles]

Sorry for another Ebby thread, I've searched and can't find a solution.

I have the D5LC system which had start up issues so I removed it, took it to local main dealer who serviced it and reported back all was ok, it was tested and ran fine on their premises, no reason to doubt this.

Fitted it back on the boat, plugged everything back in, powered up but nothing, no power even at the controller/stat switch. I've checked the 20amp/5amp blade fuses and these are fine. Used tester to establish there is power going into the ecu but there doesn't appear to be any power coming out via the harness plug that leads to the heater. The ecu appears to be a sealed unit so presumably there are no fuses in there?

I can't see any way I would have made a mistake in reconnecting the heater as the various plugs are all different types so can only connect to one another. The only issue on reconnection could have been the wires to the fuel pump, I could have reversed the polarity on this, would that have been enough to cook the ecu rather than simply blowing a fuse?

Any advice appreciated

 

[pvb]

Reversing the wires to the pump wouldn't have any adverse effect.

 

[3663Ian]

Don't worry the pump is not polarity sensitive, its just a coil of wire to form a solenoid, so you can't have destroyed the ECU simply by connecting the pump the wrong way round. Of course that hasn't fixed your problem, but I am sure a D5LC expert will be a long in a minute.

Ian

 

[David2452]

Pumps are not polarised, they are a simple solenoid. Unfortunately just because the ECU was Ok when it left the dealer it doesn't mean it still is, however the most likely culprit is a high resistance connection somewhere. Remember what you need is power not just volts so check the power in first with a high wattage bulb or other load, a meter will measure say 12v when there is not enough power to actually do anything.

 

[Bojangles]

Thanks for the replies re the pump polarity, that's reassuring.

Pumps are not polarised, they are a simple solenoid. Unfortunately just because the ECU was Ok when it left the dealer it doesn't mean it still is, however the most likely culprit is a high resistance connection somewhere. Remember what you need is power not just volts so check the power in first with a high wattage bulb or other load, a meter will measure say 12v when there is not enough power to actually do anything.

I used a small multimeter to verify there was just over 13v at the power plug into the ecu (battery charger switched off) so I reckoned that there should be some power coming out the other end? Are you saying I should connect a bulb to this end to see if there is sufficient power?

 

[cliff]

Are you saying I should connect a bulb to this end to see if there is sufficient power?

Yes 50W or better a 100W if you have one - the glow plug draws something like 20~25A on startup and the ECU needs at least 11.5v to operate IIRC

 

[Bojangles]

I've tried the bulb and plenty of power. I'm beginning to think I have been given an extra cable back with the unit from the service agent, don't know if they use a cable to attach diagnostic equipment. When I remove this cable the unit does power up.
Here's the cable in question

It was in between the black plugs shown here, in this image I have removed the "spare cable" and connected the two black plugs together

Here's the other connections

If anyone can advise if anything looks obviously wrong I'd be happy to get advice. In the meantime I've asked a local contractor to have a look, usually that means I'll have to wait a while up here..

Thanks

 

[David2452]

That does look suspiciously like an EDITH "Y" lead, but it shouldn't affect the operation, well not with the EDITH unit connected anyway, never tried without.

 

[Bojangles]

That does look suspiciously like an EDITH "Y" lead, but it shouldn't affect the operation, well not with the EDITH unit connected anyway, never tried without.

With the "y" lead in place there is no power, taking this out and connecting the 2 black plugs back together allows the unit to power up but I'm not sure if the operation was normal so I switched it off after a few minutes. Heat was coming through ok but the fuel pump was still ticking fast which I didn't think was normal.

I also see in the instructions that one of the connectors has a red dot on each side, I seem to remember having this before (but not 100% sure) so I'm going to visit the dealer and find out if they have given me the wrong cable away with the heater, if they have then they might still have one of my cables?

 

[David2452]

I'm sure they will be pleased to have it back, just looked at mine, haven't had it out for ages as it only fits pre airtronic and I don't do much with Ebers anyway, but it's the same as your pic.

 

[Bojangles]

Thanks for the info, I'll take the cable back to them.

Cheers

 

[elton]

Thanks for the replies re the pump polarity, that's reassuring.



I used a small multimeter to verify there was just over 13v at the power plug into the ecu (battery charger switched off) so I reckoned that there should be some power coming out the other end? Are you saying I should connect a bulb to this end to see if there is sufficient power?

You need to read what voltage it at the heater as it goes through the power-up cycle. Over 10 or 11 volts (can't remember exactly) is essential, otherwise it simply won't work. The voltage when the heater is off, or working normally is meaningless.

 

[Bojangles]

That does look suspiciously like an EDITH "Y" lead, but it shouldn't affect the operation, well not with the EDITH unit connected anyway, never tried without.

Thanks, took the lead back to the Ebby service agent, sure enough it was theirs. Reconnected and ran without this and changed one of the other plugs on their instruction, all seems fine. Glad to be warm again.

 

[David2452]

Thanks, took the lead back to the Ebby service agent, sure enough it was theirs. Reconnected and ran without this and changed one of the other plugs on their instruction, all seems fine. Glad to be warm again.

Pleased you are warm now, If you're not familiar with the things and somebody throws you a curve ball like that it's hardly surprising you had problems. If you hadn't posted the photo I suspect it would have been a lot more difficult to arrive at a conclusion.