1. Home
  2. Club Together
  3. Discussions
  4. Towcars & Towing
  5. Smart Alternator Technology etc.

Smart Alternator Technology etc.

Jeepman replied on 14/02/2017 17:27

Jeepman profile picture Member

Jeepman

Caravanner from Hampshire

Posted on 14/02/2017 17:27

I tow my Unicorn 3 Vigo with a 63 plate Ford Kuga. I have found that on all journeys the van fridge defrosts by the time I arrive at my destination. The cause is the smart alternator technology on the car, which turns the output off when the car's battery is fully charged. This also turns off the direct circuit to the van fridge.

I only noticed this as the fridge is a large one and more susceptible to losing cooling than the smaller ones in my previous Unicorn and Pegasus vans.

No solution from Ford, or my dealer who has carried out circuit testing on the car at Ford's behest.

Although I don't have it, a stop/start system does the same thing as on starting again the circuit to the fridge remains switched off. 

Anybody else experienced this or has a solution?

The National Caravan Council issued a paper on this in December 2016.

39 replies

Follow

JVB66 replied on 14/02/2017 17:42

JVB66 profile picture Member

JVB66

Campervanner from Hertfordshire

Posted on 14/02/2017 17:42

We have a Pegasus iv with the large fridge,and we tow with a Kia Sportage,and have the same problem ,we had the car checked at the tow bar fitters and it showed power to the fridge supply, but of course that was just a quick check,so it might be the same "problem" I feel a deeper investigation coming on!

Where can i find the ncc paper?

H B Watson replied on 14/02/2017 18:38

H B Watson profile picture Member

H B Watson

Motorhomer

Posted on 14/02/2017 18:38

You could connect the fridge feed directly to the car battery, just remember to disconnect when parked with the engine off for any length of time.

ish05 replied on 14/02/2017 22:40

ish05 profile picture Member

ish05

Posted on 14/02/2017 22:40

I had the same problem with my ix35. I put an led on the output to the fridge and found that because of the smart alternator most of the time there was no output to the fridge or battery. The easiest solution was to switch the headlights on dip, then most of the time there was an output to the fridge and battery. I have now got a Volvo with a Volvo wiring kit which seems to work okay.

ChemicalJasper replied on 15/02/2017 13:42

ChemicalJasper profile picture Member

ChemicalJasper

Caravanner

Posted on 15/02/2017 13:42

I'm not an vehicle electrician, but I am certainly confused as to why is this an issue with the smart alternator?

The feed to the van should be from a fused connection from the battery, this should provide power regardless of what the alternator is doing, if there is charge in the battery.

The supply should not be from the alternator direct (the alternator is connected to the battery) and even if it were connected to the alternator, the alternator should not switch off due to the demand from the fridge.

The alternator should just be looking after the battery.

If the supply to the van is switching off with the alternator, then there must be a switched solenoid in the permanent 12V supply to the van, this would be normal and typically be from the ignition circuit, so the fridge cannot flatten the battery in the car when the engine is not running.

Has this solenoid been wired up to a switching supply that is somehow connected to the alternator output voltage rather than the ignition on voltage?

If so, this should be an easy fix by sorting the switching input or by fitting a simple switched bypass.

CBRBlackbird replied on 15/02/2017 18:28

CBRBlackbird profile picture Member

CBRBlackbird

Caravanner

Posted on 15/02/2017 18:28

Don't know if my 12 plate Kia has 'smart alternator' technology, however the 12v feed from the 13 pin socket is only live when the engine is running.

Jeepman replied on 15/02/2017 18:29

Jeepman profile picture Member

Jeepman

Caravanner from Hampshire
Posted on 14/02/2017 17:42 by JVB66

We have a Pegasus iv with the large fridge,and we tow with a Kia Sportage,and have the same problem ,we had the car checked at the tow bar fitters and it showed power to the fridge supply, but of course that was just a quick check,so it might be the same "problem" I feel a deeper investigation coming on!

Where can i find the ncc paper?

Posted on 15/02/2017 18:29

Hope the following link enables you to read the NCC paper.

http://dmtrk.net/WP7-4OFGD-AFFGVSDZ59/cr.aspx

I have a 13 pin socket, and get constant power from pin 9, 12.5v / 14.8v, and no power from pin 10 unless the engine is running, 0v / 14.8v.

There are 3 wires connected to the battery via a fuse.

It is the car's engine management system that switches off the alternator as part of the fuel saving measures.

jeffcc replied on 15/02/2017 18:35

jeffcc profile picture Member

jeffcc

Caravanner
Posted on 15/02/2017 13:42 by ChemicalJasper
I'm not an vehicle electrician, but I am certainly confused as to why is this an issue with the smart alternator?

The feed to the van should be from a fused connection from the battery, this should provide power regardless of what the alternator is doing, if there is charge in the battery.

The supply should not be from the alternator direct (the alternator is connected to the battery) and even if it were connected to the alternator, the alternator should not switch off due to the demand from the fridge.

The alternator should just be looking after the battery.

If the supply to the van is switching off with the alternator, then there must be a switched solenoid in the permanent 12V supply to the van, this would be normal and typically be from the ignition circuit, so the fridge cannot flatten the battery in the car when the engine is not running.

Has this solenoid been wired up to a switching supply that is somehow connected to the alternator output voltage rather than the ignition on voltage?

If so, this should be an easy fix by sorting the switching input or by fitting a simple switched bypass.

Posted on 15/02/2017 18:35

Spot on cj it does sound like they have either used a direct power supply from the alternator or the split charge relay is being triggered by the alternator output instead of an ignition switched relay. Either way its an easy fix.

 

Jeff C  LAE MIMI

TonyBurton replied on 15/02/2017 20:35

TonyBurton profile picture Member

TonyBurton

Caravanner

Posted on 15/02/2017 20:35

I had the same problem on my 2015 Kuga when towing across France. If the car battery is OK,the alternator only delivers a charge when I brake. I'm not sure that simple solutions like running a wire from the car battery to the fridge is a good idea. There is some complex elecrtonics trying to control the charging voltages. I qualified as an electronice engineer back in 1967. Things seem to have changed a lot since then.

Near Malvern Hills Club Campsite by Andrew Cole

Book a late escape

There's still availability at many popular UK Club campsites - find your perfect pitch today for a last minute trip!

Book now
Woman sitting in camping chair by Wastwater in the Lake District with her two dogs and picnic blanket

Follow us on Facebook

Follow the Caravan and Motorhome Club via our official Facebook page for latest news, holiday ideas, events, activities and special offers.

Photo of Wast Water, Lake District by Sue Peace
Visit Facebook