LED Trailer Lights

**Numb Thumbs** · 4th December 2019, 02:33 PM

I have the auto electrician coming next week to wire up my 19MY SE D5 with a Redarc Tow Pro Elite and a few other things. He asked me to check and see if my car recognised LED trailer lights.

I went to the Crossover factory today, so I backed up to a couple of hybrid campers with LED tail lights - doesn't every trailer have LED tail lights now???? - and hooked it up.

The right indicator flashed the trailer icon three times and the left once, but only some of the time. So, I take it, this means the D5 does NOT recognise LED trailer lights so does NOT recognise it has a trailer attached. So Advanced Tow Assist does NOT work? Plus all the other trailer related things like turning off the rear park assist sensors when towing etc.???? Trailer stability control???

So it also means I have to install the ludicrously expensive "black box" so it will recognise trailers???? The car comes with a tow hitch plus extra towing features, yet it does not recognise nearly every new trailer out there????????? How is this moral or legal?

Cheers
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**Ferret** · 4th December 2019, 03:44 PM

If it has flashed the trailer icon even once then it recognises a trailer is attached. Sounds more like a poor connection issue to me.

And even if thats not the case you don't have to install a 'ludicrously expensive' black box. Ask your auto electrician about installing load resistors ~about $20 for the hardware.

**tony_s** · 4th December 2019, 03:54 PM

Yes, hard to believe, but if you do need the resistors you can buy them for around $20 each. You might find it easier to install them in your Vista than in the car. I think there was a thread on here earlier where owners said later model D5s recognised LEDs. My 2017 doesn’t, nor did my D4.
Tony

**Numb Thumbs** · 4th December 2019, 04:15 PM

Thanks, guys. Problem is, I have to tow many different trailers, all with LED tail lights. It has to work with them all.

The flashing icon thing was with different trailers so I don't think it was the connection. The lights worked perfectly.

I wondered about fitting load resistors in the trailer plug in the D5...

Cheers
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**Numb Thumbs** · 4th December 2019, 06:10 PM

Apparently there is a fix which is reasonably simple and cheap, but not particularly elegant. Apparently the Fords have a similar problem and there is a "dongle" available from Ford Dealers which adds the resistors to the chain:

It is $55 so guess who is off to their local Ford Dealer tomorrow??? A bit better than $700 plus much more in fitting...

Cheers
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**Tombie** · 5th December 2019, 07:50 AM

The Ford “dongle” won’t work for you.

Making up a small box to go in between will cost about $30

**IndusD4** · 5th December 2019, 08:12 AM

My MY18 has no issues recognising any trailer with LED lights, without the need for any resistors. I would check the connection as suggested above.

Ron

**Tombie** · 5th December 2019, 09:52 AM

Like all lighting, certain LED lights have sufficient numbers to draw the circuit minimum and work just fine.

Others don’t.

Door puddle lights are similar, a normal Led board isn’t sufficient, a multi Led array works perfectly.

**Numb Thumbs** · 5th December 2019, 11:26 AM

I am just back from the Ford dealer...

I got one of the dongles, drove to the camper manufacturer's factory and hooked up a camper using the dongle.

It works. $55 vs $700 plus fitting? I'll go with the dongle - not as elegant, but it works and is cheap.

Cheers
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