Towing audible alerts

[Father Ted]

Originally Posted by egor

I think you are right Father Ted, I think caravans need to have the white lights on the front, but don't quote me on that.

Sorry...I just had to quote that

[DC850]

Originally Posted by egor

I think you are right Father Ted, I think caravans need to have the white lights on the front, but don't quote me on that.

Depends on the width of the towed item and all caravans (and I mean caravans not teardrop things) that I know are of a width that require the lights.

And Egor I look up them reference about the indicator indications, with over 35 years in electronics and 25 of that in test and test development, I can not see how this new way will give you all possible failure mode indications. Mainly complete disconnection via cable break or unplugging bearing in mind most caravans/trailers and light boards are dump ie no computer to use the CAN bus

The multi bulb connections ie the front light, rear light, top red/white light and number plate light are all feed from one wire in both 13 and 7 pin plugs. this would take a lot of load measurements on that cable. As I connect up at light board, trailer and caravan which all have different light configurations, the mind bends.

[egor]

Originally Posted by DC850

Depends on the width of the towed item and all caravans (and I mean caravans not teardrop things) that I know are of a width that require the lights.

And Egor I look up them reference about the indicator indications, with over 35 years in electronics and 25 of that in test and test development, I can not see how this new way will give you all possible failure mode indications. Mainly complete disconnection via cable break or unplugging bearing in mind most caravans/trailers and light boards are dump ie no computer to use the CAN bus

The multi bulb connections ie the front light, rear light, top red/white light and number plate light are all feed from one wire in both 13 and 7 pin plugs. this would take a lot of load measurements on that cable. As I connect up at light board, trailer and caravan which all have different light configurations, the mind bends.

Thanks for the info re trailer width being the factor that determines if lights need to be fitted or not :-)

Dave, I will be taking my van for service on Monday so before I leave the storage yard I will remove bulbs one at a time and report back what info I get via the car, I have never had any blown bulbs since the wiring upgrade so I am interested to know myself (as I am sure some others will also)

P.S. on 13 pin systems pin 5 supplies Right tail / Side light & pin 7 supplies Left tail / Side light. So the front light, rear light, top red/white lights are split left / right on two wires. I will post back after I check the lights at the start of next week.

[DC850]

Originally Posted by egor

Thanks for the info re trailer width being the factor that determines if lights need to be fitted or not :-)

Dave, I will be taking my van for service on Monday so before I leave the storage yard I will remove bulbs one at a time and report back what info I get via the car, I have never had any blown bulbs since the wiring upgrade so I am interested to know myself (as I am sure some others will also)

P.S. on 13 pin systems pin 5 supplies Right tail / Side light & pin 7 supplies Left tail / Side light. So the front light, rear light, top red/white lights are split left / right on two wires. I will post back after I check the lights at the start of next week.

Gregor, Thanks that info would be useful, there is one other test might be worth doing which is, with the engine running disconnect the caravan, as this would test to see if the car is pulsing the caravan light circuit if detected at engine start. This is the only way I can think the system would give a total disconnection fault issue.

Dave...

[egor]

Good idea Dave, I will let you know the outcome :-)

Gregor

[Dullin37]

I have just fitted a Westfalia tow bar and electrics to my XC90. I was concerned by the lack of a visual indication that the caravan indicators were working after I had finished the installation. I read that if an indicator fails then this is reflected by the repeater light on the dash flashing at twice the speed.

I have tested this by removing one of the caravan indicator bulbs and sure enough, within a second or two the repeater light on the dash flashes at twice the speed. So the Westfalia dedicated wiring kit definitely uses the passive method.

[Ian21401]

I tow with a 1992 940 estate. I fitted the tow hitch and twin 7 pin electrics myself. So far as I am aware there is, or was, a requirement for an audible tone or a visible signal to indicate that the trailer was correctly connected and it's direction indicators were operating correctly. My tow hitch was delivered with a basic 12N cable and socket and a tone generator. (A small rectangular box about 2 cms x 3 cms) with two wires. For the electrics I fitted a "Logicon ZR2500" 7 way bypass relay for the 12N and a smart charge relay for the 12S. The 7 way bypass relay had an output for a visible signal. My 940 has a dedicated trailer indicator warning light within the instrument panel but the relevant wiring was not there so for simplicity I've fitted an LED in the steering column shroud. The relay also had an audible warning built in and I found this annoying, even though it is mounted in the very back of the car under the load floor, so I covered the "sound hole" with some insulation tape to mute the noise. The sound generator which came with the tow hitch is still in a box in the garage and will not be used.
With regard to the audible tone. The bypass relay I have fitted has what the manufacturer terms a "vehicle fog off, trailer fog on latch operation" This means that when the towing vehicle rear fog lights are switched on the trailer fog lights are also switched on. If the towing vehicle fog lights are then switched off (to prevent the disconcerting red glow reflecting from the front of the caravan) the trailer fog lights remain on. This causes the relay to emit a 1 second tone each minute as a reminder that the trailer fog lights are still on. To switch off the trailer fog lights the towing vehicle fog light switch must be turned on again and then off. That may be what you could hear. If your foglights will only light up if you have other lights lit then the act of switching headlights off and on etc. may have switched your foglights on and off again, so disabling the warning tone.
I'm not a fan of the passive system. I'd much prefer to stay with the active system which I've always known.

[green van man]

I have just today been in contact with the supplying dealer of my new to me car about this. Volvo in their wisdom chose to give a simple problem a complicated solution, this I think is the problem with having computers controlling cars, you have to find things for them to do.
However I digress, the purpose of the post was to confirm that if you remove an indicator lamp from the trailer the dash repeater flashes twice as fast, also just refitting the lamp does not cancel the rapid flashing, to do that the ignition has to be cycled off and on.
I did not try it but by that reasoning if one of the other trailer lights failed the failed lamp symbol should illuminate on the dash. Will try that asap with the trailer board.
Out of habit I have always towed with at least sidelights on as the forward ffacing white lights are visable in my mirrors and an indication of things going arwry if they suddenly disapear .
No doubt we will learn to cope with the new system, no matter that we think it a silly idea. It is legal in UK as I specifically questioned it with dealer and he with Volvo. To judge by some of the shocking sites I see daily with towed caravans not many plod seem to know the laws anyway, which is no excuse but does give us a fighting chance of arguing our case.
Paul.

[egor]

Originally Posted by DC850

Gregor, Thanks that info would be useful, there is one other test might be worth doing which is, with the engine running disconnect the caravan, as this would test to see if the car is pulsing the caravan light circuit if detected at engine start. This is the only way I can think the system would give a total disconnection fault issue.

Dave...

Sorry for taking so long to come back to you on this, I have been very busy with various things and haven't been using the computer for non work stuff for weeks.

Anyway as green van man said, you only get the double flash on the turn signal indicator light on the dash if a bulb has blown.(you don't even get the little green trailer light anymore) nothing for brake lights! nothing if you disconnect the caravan from the car! so all in all it is no further advanced than cars decades old!! So I went to my local dealer and spoke to them at length, apparently the new TCM (trailer control module) is all about caravans that have LED side lights (as my van does) apparently without this new TCM the led lights 'can' play funny buggers and come on and off with other lights i.e. indicators, brakes and so on, they can also strobe as well. So my money was not a wasted however I do think that things should be a wee bit more advanced in 2014!! the master tech did point out that although I have a fairly modern van that is kept in good order, I could also pull an old rusty trailer out of a field with dodgy electrics, so the car would have a very difficult job of knowing what was happening unless all trailer electrics were made and operated to the same standard. So I guess he has a point.

Gregor

[DC850]

Originally Posted by egor

Sorry for taking so long to come back to you on this, I have been very busy with various things and haven't been using the computer for non work stuff for weeks.

Anyway as green van man said, you only get the double flash on the turn signal indicator light on the dash if a bulb has blown.(you don't even get the little green trailer light anymore) nothing for brake lights! nothing if you disconnect the caravan from the car! so all in all it is no further advanced than cars decades old!! So I went to my local dealer and spoke to them at length, apparently the new TCM (trailer control module) is all about caravans that have LED side lights (as my van does) apparently without this new TCM the led lights 'can' play funny buggers and come on and off with other lights i.e. indicators, brakes and so on, they can also strobe as well. So my money was not a wasted however I do think that things should be a wee bit more advanced in 2014!! the master tech did point out that although I have a fairly modern van that is kept in good order, I could also pull an old rusty trailer out of a field with dodgy electrics, so the car would have a very difficult job of knowing what was happening unless all trailer electrics were made and operated to the same standard. So I guess he has a point.

Gregor

So no indication should the plug fall out or cable snapping due to not enough slack on a tight turn, that could happen on a trip and you'll be non the wiser that your trailer/caravan has no lights oh well we move on or do we?