Post by Mike Harding on Jul 27, 2024 13:28:35 GMT 10
My car/caravan has a 12 pin rectangular connector for electrical connection between the two; this style of connector is mandated in the Australian Standard relating to towing - unfortunately it's a very poor quality connector.
Those of you who understand how standards' committees work may reach your own conclusions as to why such such a derisory and inadequate product was nominated, I'll say no more on that issue.
Image of connector style
I bought this car new about four years ago and subsequently had a competent auto electrician fit both a Redarc proportional brake controller and a 12 pin socket.
A few days past when towing my caravan two other kind road users informed me the brake lights on my van were not working. Upon examination it was revealed the van's RH indicator was also faulty. Investigation indicated the fault to be in the plug of the aforementioned connector.
The problem relates to the pin and socket design of this style connector. As may be seen in the photograph each pin has a slit cut into it which allows the pin diameter to be slightly larger than the socket and thus provides outward pressure from the pin to the socket walls aiding good electrical contact. The trouble is the temper in the pin metal diminishes over time and that slit closest up and loses its "spring-e-ness" after which electrical contact is either poor or non existent.
Losing rear lights on a caravan is a problem and illegal but unlikely to lead to significant safety issues. However what really troubles me here is that the caravan brake circuit is also carried by the same connector and, I later realised, that circuit had failed too!
As mentioned I had a modern, expensive, Redarc proportional brake controller fitted; this controller senses how hard the car is braking and applies a proportional amount of braking to the caravan. I'm a pretty smooth driver and seldom need to brake much beyond a light touch of the pedal so I hadn't noticed the van brakes were not working and that the car was carrying the whole effort for both itself and 3T of caravan! Had an emergency situation occurred I dread to think what may have happened.
Fundamentally the design of these connectors is flawed and they will always deteriorate and eventually fail.
My plan is to extend the wiring for brake lights, indicators and caravan brake out of this connector and into a professional IP67 connector. This will leave both car and caravan compatible with other tow vehicles but will eliminate the issues of this dreadful 12 pin connector.
NB. Seven pin and round connectors also use the split pin technique - I suggest you check all lighting monthly.
Those of you who understand how standards' committees work may reach your own conclusions as to why such such a derisory and inadequate product was nominated, I'll say no more on that issue.
Image of connector style
I bought this car new about four years ago and subsequently had a competent auto electrician fit both a Redarc proportional brake controller and a 12 pin socket.
A few days past when towing my caravan two other kind road users informed me the brake lights on my van were not working. Upon examination it was revealed the van's RH indicator was also faulty. Investigation indicated the fault to be in the plug of the aforementioned connector.
The problem relates to the pin and socket design of this style connector. As may be seen in the photograph each pin has a slit cut into it which allows the pin diameter to be slightly larger than the socket and thus provides outward pressure from the pin to the socket walls aiding good electrical contact. The trouble is the temper in the pin metal diminishes over time and that slit closest up and loses its "spring-e-ness" after which electrical contact is either poor or non existent.
Losing rear lights on a caravan is a problem and illegal but unlikely to lead to significant safety issues. However what really troubles me here is that the caravan brake circuit is also carried by the same connector and, I later realised, that circuit had failed too!
As mentioned I had a modern, expensive, Redarc proportional brake controller fitted; this controller senses how hard the car is braking and applies a proportional amount of braking to the caravan. I'm a pretty smooth driver and seldom need to brake much beyond a light touch of the pedal so I hadn't noticed the van brakes were not working and that the car was carrying the whole effort for both itself and 3T of caravan! Had an emergency situation occurred I dread to think what may have happened.
Fundamentally the design of these connectors is flawed and they will always deteriorate and eventually fail.
My plan is to extend the wiring for brake lights, indicators and caravan brake out of this connector and into a professional IP67 connector. This will leave both car and caravan compatible with other tow vehicles but will eliminate the issues of this dreadful 12 pin connector.
NB. Seven pin and round connectors also use the split pin technique - I suggest you check all lighting monthly.
