Hi Peps, just recently got a towbar fitted to my jayco motorhome in preparation for a small tow vehicle to go on, picked the car up, attached it to motorhome and found not only lights on tow vehicle not working but lights on motorhome not working with tow vehicle plug attached, disconnected tow vehicle plug lights on motorhome working again, (very strange indeed), got vehicle home so attached it to my ute which has a standard plug connection same as motorhome, all lights working on both vehicles??, now I am confused, took tow vehicle up to place of fitting on back of ute to show them, they had a strange look on their face as what the problem could be as same plug connection on both ute and motorhome and they swear the plugs are both wired the same, has anybody had the same issues or similar?? or has anybody got any ideas as i am taking tow vehicle attached to motorhome to them today. Motorhome is a fiat ducato 2011 model....thanks in advance
hi, tow car is a suzuki swift, suzuki lights are wired to a fixed female plug on front of car, lights work perfect using same connecting lead as used on the motorhome on the ute, so that wipes out plug connection on suzuki and connecting lead, i did ask the installer to check the ute wiring with suzuki attached so when i take motorhome up he has something to compare with and against. but as all installers are never wrong general attitude was its a standard plug connection no need to check it, he did say we checked the wiring as we always do on every install and its correct, so i suppose i am at their mercy, personally i think the wiring is incorrect unless somebody has a different view or experienced the same issue, and to think all it would have taken was to check the ute wiring to compare motorhome wiring for when i take the motorhome to them, the mind boggles at times how installers fail to think outside the square. The main and only issue is all lights work fine when attached to ute, no lights work when attached to motorhome not even the motorhome lights work when attached.
Could depend on manufacturer of "Motorhome" not the cab chassis manufacturer - Large fabricator located in Sydney advised Australian Standards are only recommendations therefore they don't have to comply them (in writing), Unbelievable but true.
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Possum; AKA:- Ali El-Aziz Mohamed Gundawiathan
Sent from my imperial66 typewriter using carrier pigeon, message sticks and smoke signals.
Hi peps, just received an email back from towbars australia stating they should have supplied and installed an ECU unit as all modern day cars require this when wiring up lights for towing connection
Once again Macka, an illustration of your understanding of modern vehicles and the electronics that are associated with them. If you dont know the answer, Shut up.
The issue had nothing to do with apprentices, earthing, revering wiring, or or for that matter, dodgy plugs. and I am surprised that Cranes, Drag Lines, Yachts, Generators and cyclones weren't mentioned.
On rare occasions you do give valuable advice, but at other times you dribble on.
" ECU unit as all modern day cars require this when wiring up lights for towing connection", not totally correct, my vehicle uses relays off each circuit, the relay actuation current undetected by the computer. This is another way the job can be done.
My Ranger has a cutout relay at 1/2 the current that my Falcon had. My van (4 tail lights) worked OK on the Falcon but not the Ranger. Took out 2 globes and all is now OK. It was like dragging teeth to get that info off Ford. The dealer was really embarrassed about Ford's lack of co-operation. Cannot remember the current limit for the Ranger, but removing two worked as Ford finally admitted to.
Modern vehicles don't rely on fuses to protect lighting circuits, they use a fundamental property of transistors to control, measure and test the power supplied to each lighting 'unit'. The very name 'transistor' describes this property - trans (meaning changes) and resistor, so the name means a changeable resistance. Turned off a transistor has very high resistance (no flow), partially turned on a transistor has a well defined amount of resistance (controlled amplification), and fully turned on it has almost no resistance (useful as an off/on switch).
Almost no resistance is not the same as no resistance. This is the property used by vehicle light control units (LCU) to test lighting units. The very small amount of resistance across a transistor when it is turned 'fully on' will change according to whether the the circuit is shorted, open or the wrong load. A voltage difference will show across the resistance and this is simple to measure - 1) An open circuit will show no voltage, 2) The correct load will have a small, known voltage while 3) Higher loads (extra lights or a short circuit) will have some higher voltage level.
The light control unit computer will continuously test the lighting units with full-on pulses (at very small times per pulse) and respond accordingly. Extra load from wiring a trailer in parallel with existing tail lights will result in a severe warning or even shut down of a lighting circuit. If LED lights are fitted to a trailer they may flash with every test, every few seconds.
So what is the solution if splicing in to exixting wiring won't work?
* Some motor vehicle manufacturers have LCUs that see double load on tail light circuits as evidence that a trailer is attached and adjust behaviour accordingly. This is rare.
* Many vehicle manufacturers duplicate the outputs at very low power, requiring a second Trailer LCU to actually operate and test the trailer lights. This is common and makes $$$ for the manufacturer.
* Third party 'Pulse Busta' units may be imposed between the vehicle LCU and the trailer connection. These have 'high impedance' inputs that hardly change the resistance across the LCU's transistors so they go undetected. These are effectively the same as a 'genuine' Trailer LCU but without the testing and reporting. A solution of sorts, but the genuine Trailer LCU is better, particularly if the tow vehicle has traction control or ride leveling built in (these will not be adjusted if no trailer is reported by the T LCU).
* Relay Repeaters that add about 90 ohms to each lighting circuit and may or may not be detected by a LCU. Probably works with vehicles built up to 2010, but not for newer ones.
* Put up with the warning messages and double flash rate for 'faulty' indicators when no trailer is detected but extra load is added. Not a solution at all. Should only be used in emergency situations.
I personally think that any vehicle advertized as 'tow capable' should have a 'tow ready' LCU factory fitted. I live in hope ...
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Bruce & Judy pulling a 3T 23.5' Traveller Prodigy behind a Diesel Range Rover
You have summed up what I got from Ford. I tried to put LEDs in because the existing globes drew too much and subsequently stopped working until next time I started the Ranger. Then stopped first use. However LED's don't drag enough and cause the cut-out to switch in-out-in-out.... resulting in my brake lights flashing like an indicator.
