Trailer Light Connections

[freddysolar]

Hi,
Had a Hayman Reece Towbar and trailer light connection socket fitted to my NS Exceed in Qld (organised by the Pajero dealer when vehicle delivered).
All lights checked OK on a short test, then set off for Melbourne towing the caravan.
That evening I turned tail lights on, which turns on caravan tail and clearance lights. Then, after about 1 minute, all caravan lights turned off and stayed off. I turned Pajero lights off for 5 minutes, then on again which enabled the caravan lights. Once again, they switched off after about 1 minute.
I suspected an overload due to the extra caravan lights tripping an auto-reset relay or some other protection device in the Pajero.
The total wattage of the caravan lights is approximately 80 watts (about 6 Amp draw).
On arrival in Melbourne, I contacted Hayman Reece and they sent me to one of their authorised installers. The installers advised they have this problem with Mercedes Benz and BMW!
Cutting a long story short, they fitted a 40A relay enabled by the Pajero tail lights and a heavy source of 12V power taken from the Cigarette lighter 12V socket in the rear compartment. Cost me about $150. All now works fine.
I consider this to be a jerry-rig fix (although quite suitable for the purpose).
Surely Pajero has a suitable trailer light source take-off point that can carry the 12V load of a caravan??
Can anyone offer some comment or advice on this.
(incidentally, this is the 2nd time I have tried to send this post - hope it doesn't turn up twice....)
Best regards, Fred

[pajman]

Fred, Can i ask a question is the lighter in the back of the NS wired directly or is accessories needed. On the weekend I went away for the night and noticed that no lighter in the Ns was wired directly and that the ignition had to be on. Is this the same as yours.... Sorry I cannot help with the carvan as I have not towed a caravan yet, only camper trailer...

Cheers

[mikens]

Fred, Can't comment on your situation, but when i got my camper-trailer connected up, I noticed that all the lights were around the wrong way (left/right indicators, and park lights/brake lights). At first I thought the trailer was wrong, but no, it was MM who had the tow bar installed pre-delivery!! Thanks very much MM! Mikens

[freddysolar]

Fred, Can i ask a question is the lighter in the back of the NS wired directly or is accessories needed. On the weekend I went away for the night and noticed that no lighter in the Ns was wired directly and that the ignition had to be on. Is this the same as yours.... Sorry I cannot help with the carvan as I have not towed a caravan yet, only camper trailer...

Cheers

Hi Pajman,
Lighter outlets in front dash near radio and the rear compartment are only powered up when ign/accessories is on. I do not know about the outlet in the centre console/arm rest box as I have never used it.
Regards, Fred.

[Mike DiD]

Fred, Can i ask a question is the lighter in the back of the NS wired directly or is accessories needed. On the weekend I went away for the night and noticed that no lighter in the Ns was wired directly and that the ignition had to be on. Is this the same as yours Cheers

The easiest way to get permanent power to the Accessory sockets in teh armrest and luggage compartment is to bypass the Relay under the dash with a heavy wire across the big contacts. The socket at the base of the dash does not connect via a Relay.

The socket in the luggage compartment will have excessive voltage drop if you try to draw more than 5 amps from it.

[phoenie77]

Back on the Trailer connection, anyone else had issues with no power at the trailer plug. I have lost power to my plug this week for no apparent reason and MM blmaing my Compressor, Inverter or anything else electrical as a possibility. I have a genuine Towbar fitted by the dealer and have found that there is a small module in behind the Drivers side Tail Lamp that appears to be to go to the trailer plug wiring. I took it to the dealer today who looked at it and said the fusible link had blown which they replaced but still no power to the plug. They wanted me to book it in next week for them to get an Auto Sparky to look at it but as i am towing my camper trailer this long weekend i have had to book it in at my own Auto Sparky at my own cost. It seems verys strange to have lost power to every pin for no apparent reason. I towed a mates trailer at christmas time when it worked fine and plugged my camper in to check on the weekend to find nothing.

[Eddy Lah]

Hi Phonnie77, am having exactly the same problems, at first it was the fuse that was blowing, now fuse is OK but no power into the socket, would be very interested to hear what you have found!!

[Walker]

WOW. I cant believe this. When you say you have no power do you mean just the 12v active or you have no blinkers/stoplights ect.

I have just arrived home from a week at Robe. I towed the caravan down there and just before arriving I last all my lights on the caravan. I checked the fuse and it had blown. I replaced the fuse and it all worked fine again. I thought I would check it all a couple of days ago before coming home and found that I had now power at the trailer plug again. I checked the fuse and it was ok this time.
I rang up the service department at a Mitsubishi dealer on Saturday morning and we went through it all over the phone. Apparently the NS has a BCU to control the trailer wiring. All the wiring to the BCU is fibre oprics hence the power cable and fuse from the battery. The best we could work out is that the BCU is faulty or has blown up. I was told that you cant even rig a temporary loom from the rear lights as the ECU will pick up the voltage difference and cause problems.

I was stuck with 2 choices. I could take the car or getit towed to Mount Gambier where I would have to wait till Tuesday for the Dealer to look at it or I could drive home with no lights. I ended up driving home with friends following behind making sure they were the only car directly behind me.


Not sure if it is just coincidence or not but when I lost power it was pouring with rain.

[Eddy Lah]

Hi Walker, yep like you said, got no blinkers, stop lights, tail or anything, checked conections on car plug and no power coming from any poles, , must mention that I use my car to launch and retrieve my boat as well , so thinkl water in the trailer conections may have a lot to do with it!!! Going to sparky guy with boat trailer attached , in morning and let him have another go, try no 3!!!, don't like the sound of computer module blowing up!!!


Eddy

[Walker]

I had Mitsubishi install my towbar when I bought it so I will just be taking it back to them. I have researched it a bit more and I can almost guarantee the problem will be with the BCU, there is nothing else it can be.

[Eddy Lah]

For your and Mine sake I hope so, as we did'nt order cars with tow bars {Boss's oversight}, had ARB towbars fitted , with the proper Mitsubishi trailer wiring kit, and local sparky wired it all up, so hope he got it right!!!. have had it back to him on three occasions now, tommorow will be No. 4!!!, previously was fuses!!! or so he told me!!!


Cheers


Eddy

[matthewfnorbert]

i believe mine has a little gadget in the rear that sends the signals (relay) to the trailer to isolate the trailer from the truck elect system.. this has a fuse.. is this the BCU? my previous modern vehicles have had this also.. the mercs,bmw,vw etc all use the same one for say a hayman reece tow bar, don't recall them being too expensive ....

[Jeff_P]

Hi all, just a quick thought re this, what type of plugs are you using? I just had a towbar fitted by MM as we had bought a new boat and want to tow it with the Paj. When it came home with the wife it had a flat plug not the round one I expected and assumed would be fitted. When I queried the plug type with the dealer he stated that MM require the flat plug as opposed to the "standard" round 5/7 pins as the electrics require the flat plug or else there can be problems with the vehicle, this included other MM vehicles as well not just the Paj. So, down to the auto shop and to buy a flat to round connector/converter, another $30 I didn't want to spend.
Cheers

[Walker]

My last 4 vehicles have all had the flat 7 pin plugs, I think they are a much better plug although I can't understand why a round plug would cause any problems.

One thing I did notice is that the flat 7 pin plug had 2 extra terminlas in the back. So the trailer wire as actually 9 wire. There was a smaller diameter grey and pink wire which were terminated at the plug. I have absolutley no idea what they are for and have never seen them before.


Matt, yes the converter "thingamajig" in the back will be the BCU. I might see if I can get access to it and see if it has an easily accesable fuse on it, but I would not be surprised if it was just a just on the circuit board. Now I just have to work out where it is. I would guess it is behind the far rear trim panel on the right side.

[matthewfnorbert]

Hi all, just a quick thought re this, what type of plugs are you using? I just had a towbar fitted by MM as we had bought a new boat and want to tow it with the Paj. When it came home with the wife it had a flat plug not the round one I expected and assumed would be fitted. When I queried the plug type with the dealer he stated that MM require the flat plug as opposed to the "standard" round 5/7 pins as the electrics require the flat plug or else there can be problems with the vehicle, this included other MM vehicles as well not just the Paj. So, down to the auto shop and to buy a flat to round connector/converter, another $30 I didn't want to spend.
Cheers

more rubbish, these guys amaze me

does not matter what plug you use so long as the wiring/pin convention you follow is the same. you can fit a round plug if you wish.. now you have an adapter which can cause you problems as all the plugs i have seen local are rubbish quality.

i hate the flat 7 pin as they are poor quality, the euro round 7 pin are great quality for eg.