Burning smell from Electro block

[Jim Schush]

Whilst driving home from a few days away this morning we noticed a burning plastic smell coming from the electro block under the passenger seat.
The smell disappears when the 12v is turned off and after a bit of checking what was on, we turned the 12 v back on but turned the fridge off, the smell stops.
All the electric still work fine on both 12v and hook up.
All connections into the block look fine but I will have another look tomorrow.
Anyone experience anything like this before?

 

[Figaro]

I've heard of the fridge EBL connection becoming blackened, presumably due to arcing from a poor connection.
Would be worth checking them all throughly.

 

[RedFrame]

I've heard of the fridge EBL connection becoming blackened, presumably due to arcing from a poor connection.
Would be worth checking them all throughly.

Agree, we had a similar problem, check the fridge 12v connection on the ebl for arcing.

Cheers
Red.

 

[autorouter]

Which EBL model number is it? Many have a 4-way connector for the fridge output, worth having a close look at that.

 

[Jim Schush]

Which EBL model number is it? Many have a 4-way connector for the fridge output, worth having a close look at that.

It’s the 119 EBL. Thanks for the advice I will check it out today.

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[autorouter]

The supply for the fridge 12V heater element comes in from the starter battery via the 5-way connector. It goes through the fridge relay inside the EBL. Then out to the fridge via the 4-way connector. Usually it only comes on when the engine is running. It is a high power circuit, about 15A, which is about the limit of the connector terminals. If they are not 100% perfect and show a slight resistance, they start to heat up. That makes the resistance increase more, so more heating, etc. It can get hot enough to melt the plastic connector shell.

The fuse doesn't blow because there's not actually any more power being drawn. What's happening is the heating is ocurring in the connector instead of the fridge heater element.

The supply for the fridge control board is entirely separate, and comes from the leisure battery via one of the other fuses. It's a low power circuit that usually gives no trouble.

The connectors are Mate'N'Lok (MNL) type, available from auto electrical suppliers. They come with separate pins, which you crimp into the wire. Then push the pin into the back of the connector shell. A couple of small barbs lock it in place.

Mate N Lok Universal Connector Pair - 4 Way

4 way Mate N Lok connectors for 0.5-2.0mm² cable provide secure and robust multiple connections. Supplied as a pair of male/female housings with all terminals.

www.12voltplanet.co.uk

You might need to replace the connector on the EBL front panel, which requires soldering. It's not a difficult job for someone who can solder connectors to circuit boards. Schaudt, the manufacturer, do a repair service, which I have used in the past. But with the current situation posting across the border, you might be better with Apuljack Electronics who also repair EBLs.

Apuljack Electronics

default meta description (ContentText_DefaultMetaDescription)

www.apuljackelectronics.co.uk

 

[ivorantony]

Apuljack is a very interesting website to look through, they seem to do modifications to the charging units on most motorhomes to allow lithium charging. This would be much cheaper than replacing with a bespoke lithium charger.
food for thought ?

 

[Jim Schush]

The supply for the fridge 12V heater element comes in from the starter battery via the 5-way connector. It goes through the fridge relay inside the EBL. Then out to the fridge via the 4-way connector. Usually it only comes on when the engine is running. It is a high power circuit, about 15A, which is about the limit of the connector terminals. If they are not 100% perfect and show a slight resistance, they start to heat up. That makes the resistance increase more, so more heating, etc. It can get hot enough to melt the plastic connector shell.

The fuse doesn't blow because there's not actually any more power being drawn. What's happening is the heating is ocurring in the connector instead of the fridge heater element.

The supply for the fridge control board is entirely separate, and comes from the leisure battery via one of the other fuses. It's a low power circuit that usually gives no trouble.

The connectors are Mate'N'Lok (MNL) type, available from auto electrical suppliers. They come with separate pins, which you crimp into the wire. Then push the pin into the back of the connector shell. A couple of small barbs lock it in place.

Mate N Lok Universal Connector Pair - 4 Way

4 way Mate N Lok connectors for 0.5-2.0mm² cable provide secure and robust multiple connections. Supplied as a pair of male/female housings with all terminals.

www.12voltplanet.co.uk

You might need to replace the connector on the EBL front panel, which requires soldering. It's not a difficult job for someone who can solder connectors to circuit boards. Schaudt, the manufacturer, do a repair service, which I have used in the past. But with the current situation posting across the border, you might be better with Apuljack Electronics who also repair EBLs.

Apuljack Electronics

default meta description (ContentText_DefaultMetaDescription)

www.apuljackelectronics.co.uk

Thank you for your detailed response. I have had another look at the connections on the EBL unit and can’t see any evidence of discolouration.
I have arranged to have the vehicle looked at by a qualified professional and I will update the post when I know more.
Thanks for your help.

 

[RedFrame]

Make sure you uncouple the MNL connector and check the pins, ours looked fine from the outside

Cheers
Red.

 

[Rjcamper]

Had the same, couldn't see anything, could smell burning, felt wires and where red hot. Took board out and all blackened, burnt and had to send board away for repair.

Luckily had enough slack on the fridge 12v supply to cut back and recrimp once board back

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[Delboyarapaho]

Apuljack are great very responsive and helpful on the phone. Provided me an exchange and fitted it while I waited

 

[wfdTamar]

I recently needed to have my EBL repaired and consider Schaudt, Apuljack and AandNCaravanServices. The bloke at Schaudt responded very fast, but I thought it might add shipping expense and time to get it done. I considered Apuljack due to the lithium capable charger option, however it's only capable of lithium. It can't do the other battery types. As I wasn't yet willing to go to lithium, their repair cost was too high.

So I went with AandN who were fast and much cheaper - £130 plus shipping. That was to repair the charging circuit. He is a fussy sod about the box and packing and charged me £8 to repack it in a box hardly any different to what I sent it in. Basically about an inch all around to spare padded with bubble wrap.

 

[Jim Schush]

The Electroblock has now been returned from A & N caravan services with no fault found (great service and returned in 5 days).
So with no faults found I am going to refit the unit today and see if the smell comes back.
Could I ask in terms of refitting the EBL unit is there a order to refit the 3 wires on the back of the unit.
Thanks for your help.

 

[autorouter]

I can't think of a reason to choose a particular order. When replacing starter or leisure batteries they say positive first, then negative, but I don't think that applies here.

If you have solar, some solar controllers need battery first, then panels. So you have to disconnect the panels, connect the EBL/battery, then connect the panels

 

[Cookieboy68]

I recently needed to have my EBL repaired and consider Schaudt, Apuljack and AandNCaravanServices. The bloke at Schaudt responded very fast, but I thought it might add shipping expense and time to get it done. I considered Apuljack due to the lithium capable charger option, however it's only capable of lithium. It can't do the other battery types. As I wasn't yet willing to go to lithium, their repair cost was too high.

So I went with AandN who were fast and much cheaper - £130 plus shipping. That was to repair the charging circuit. He is a fussy sod about the box and packing and charged me £8 to repack it in a box hardly any different to what I sent it in. Basically about an inch all around to spare padded with bubble wrap.

Yes I got charged £8 for repackaging, but happy with the quick turnaround. and ebl working as it should

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[Jim Schush]

We have finally discovered where the plastic burning smell is coming from today.
Remember the smell only happens while driving with the fridge on.
Under the passenger seat at the side of the Schaudt EBL there’s a 13 pole electrical connector, it appears the live wire has caused the plastic separator to melt and the wire it self looks charred.
I have booked a auto electrician to have a look at it and see if we can determine what caused it.
Thanks for all help on this as a few people suggested a poor electrical connection.