# Problems with my Elektroblok 105-3, can you help?



## Rincewind (Jun 24, 2009)

In case it is relevant the Elektroblok is fitted in a 1998 Hymer e650 on a long wheelbase Ducato 2.5 chassis.

I seem to have two problems which I don't think are related but you never know!

The main problem is the 12v supply doesn't stay at 12v, it drops until the AES system detects the low volts and turns the fridge off. I have downloaded the wiring diagram (in German so have googled translations, which don't all seem to make sense but heyho) and got my trusty multimeter out to check what is going on.

Ok. Battery 1 (Starter battery) at 12.5v, check input to Elektroblok 0v as I expected as engine not running. Start engine, 11.5v , so have now lost a volt, then after 30sec perhaps a minute the voltage suddenly drops another volt to 10.5. I am guessing this second drop is when the fridge has worked out that it should be using 12v and switches the 12v heater on. I also checked the D+ and this is maintained at a bit over 14v so the alternator is doing it's business.

So where are my volts going, my thinking is that there is a relay or similar on the Ducato which is going a bit high resistant, does this sound about right and does anyone know of such a thing and if so what does it look like and were is it?

Now the second even more taxing problem, there is a 2A fuse under the bonnet which keeps blowing. The fuse holder connects to the starter battery on one side and the other disappears into the cab. Looking at the circuit diagram I think it should go to "fuhler B2" (translates as feeler/antennae???) which appears to only go to the volt meter on the control panel. I can't work out what is blowing the fuse, it has been OK for weeks the another time it goes within hours, I can't discover what is operating and causing the problem.

Does anyone have any ideas, have you actually managed to read all the way to the end!! Also I can't see how the Starter battery is charged from the elektroblok, could this be part of the charging system? The reason for asking is that without this fuse the battery meter doesn't work but with either mains connected or the engine running it does, so power is getting to the meter, I wonder if it then should go to the battery to keep it topped up, confused, I am.

Any help would be appreciated.......thanks

Keith


----------



## clive1821 (Mar 27, 2010)

The main battery#1 is charged from the mains psu via..RE2 R9 D9 and on ward to the main battery... its a low current charge about 2 to 5 amps if i recall


----------



## clive1821 (Mar 27, 2010)

Just to check first the volts on battery#1 when the engine is running is 14.00V or there abouts? if so what are the volts like on battery#2 ? which is on the rear of the elb should be very similar.... if not RE5 comes into play.... all with the engine running..... now also check the volts on the mains psu LA204 with the mains conected... should be around 14.00v... if not there a good reason why the leasure battery is not charged.... there are so may variables to faul finding its very difficialt to do without seeing the fault.... still hope that helps... and of course the D+ and could well be the diode accross one of the relays gone short circuit as well...


----------



## pieterv (Feb 3, 2009)

Just my little bit, not a resolution to the problem, but the German Fuhler means sensor.


----------



## Rincewind (Jun 24, 2009)

Hi Clive,

That was lots of help, I have now managed to work out a fair bit of how it all works....thanks!

I have been out to the van to recheck a few bits and of course it is all producing the right kind of figures!!!

It seems both RE2 and RE5 are switching OK as I got the expected changes with engine on/off, mains on/off. Haven't been able to measure the direct output from LA 204 but both batteries are at 13.05v's which I think is slowly coming up as they charge.

So at the moment the previous figures are a mystery, just need to keep an eye on things, which should be easier now I know what I am looking for.

A couple of other things, is R1 Shunt some form of current measuring device for the meter above the door and is R9 a variable resistor?

Thanks for your help, it is bloomin' ages since I have had to do any electrical fault finding so struggling a bit!

Regards

keith


----------



## clive1821 (Mar 27, 2010)

Hi Keith, Yes R9 is a thomistor resister... just gives a very low charge current.... and R1 is the main shunt which shows you the total current being consumed and or a charge current... hope that helps...


----------



## Rincewind (Jun 24, 2009)

Brilliant, I think I understand most of the circuit diagram now.

Many thanks

Keith


----------

