16' Series Query on auxiliary power to Caravan

Big Al

Member
Jul 23, 2012
66
10
8
Wondering if anyone has any information on why auxiliary power is not working from trailer plug from vehicle.
I have power going into the plug of the caravan but lights (in caravan) are still not working.
2012 Jayco Expanda.
 

Bank of Dad

Well-Known Member
Jul 20, 2011
713
361
63
Kilmore, VIC
Do you mean the interior lights of the van or the brake/indicator/tail lights?

Does the van have a battery fitted and is the battery switch (if fitted) on?
 

Big Al

Member
Jul 23, 2012
66
10
8
Do you mean the interior lights of the van or the brake/indicator/tail lights?

Does the van have a battery fitted and is the battery switch (if fitted) on?

The interior van lights are not working.The battery has not been fitted.
 

boots33

Well-Known Member
Jun 25, 2011
708
679
93
Maudsland Gold Coast Hinterland Qld
The setec power unit will disconnect the van battery from your circuits once it falls below 10.5v. So without the battery fitted the setec will be thinking you have a flat battery and will have isolated the battery. unfortunately this also will disconnect the 12v aux in circuit as well, a rather dopey way of doing things but that is how it works. this means that without a battery fitted the only way for you lights to work will be to have 240v connected. The only way round this will be to move your aux in wire and connect it to the wire that would normally connect to the positive terminal of the van battery. This will trick the setec into thinking you have a battery fitted and your lights etc will work when the car is connected. have a look here and you can see the wire marked AUX IN +VE that is the wire that you have to move. Or of course you could just fit a battery :)
 

Big Al

Member
Jul 23, 2012
66
10
8
The setec power unit will disconnect the van battery from your circuits once it falls below 10.5v. So without the battery fitted the setec will be thinking you have a flat battery and will have isolated the battery. unfortunately this also will disconnect the 12v aux in circuit as well, a rather dopey way of doing things but that is how it works. this means that without a battery fitted the only way for you lights to work will be to have 240v connected. The only way round this will be to move your aux in wire and connect it to the wire that would normally connect to the positive terminal of the van battery. This will trick the setec into thinking you have a battery fitted and your lights etc will work when the car is connected. have a look here and you can see the wire marked AUX IN +VE that is the wire that you have to move. Or of course you could just fit a battery :)

Thanks for that information you have been the greatest help
i think iwill just fit a battery.Every thing is there to fit one.
Funny thing is at jayco when i picked it up and i connected to my car it did not work.They tried their test trailer plug which had its own battery and lights worked ?I went home and tested my plug and it had power going into the aux wire to the van.I even checked earth wires ok very strange.
 

boots33

Well-Known Member
Jun 25, 2011
708
679
93
Maudsland Gold Coast Hinterland Qld
Very strange indeed. did they offer any idea why theirs worked and yours did not. Unless setec have made changes to the current model st unit i don't think it should have worked. they didnt have 240v connected at the time ? If you do end up fitting a battery you should check to see if you are getting a charge from you vehicle just to be sure.
 

Feldty

Member
May 31, 2012
129
7
18
Wangaratta, Vic
Just a thought, if the Setec Unit cuts out at 10.5 volts, could it be a voltage drop issue. It is a fairly long run of wire from the start battery to the caravan.

You could try starting the vehicle, this would increase voltage and may give you a clue. This would explain why theirs worked and yours did not, as they may not have had the length of cable to affect the voltage, or had a higher voltage in there battery to start with.

Good luck.
 

Big Al

Member
Jul 23, 2012
66
10
8
Just a thought, if the Setec Unit cuts out at 10.5 volts, could it be a voltage drop issue. It is a fairly long run of wire from the start battery to the caravan.

You could try starting the vehicle, this would increase voltage and may give you a clue. This would explain why theirs worked and yours did not, as they may not have had the length of cable to affect the voltage, or had a higher voltage in there battery to start with.

Good luck.

Again thank you for your help .I will try some things
 

coled1970

Well-Known Member
May 27, 2012
374
308
63
Hunter Valley, Newcastle
Hey Big Al,

In our 14' there is a main light switch near the door turns all power off to the lights even when on 240v or battery.(this is different to the main battery switch). Not sure if your van is the same or not.
 

ElectricGuru

Member
Sep 5, 2011
189
22
18
SE Brisbane
Hey Big Al

Firstly, I would check that the car socket is the same as the standard pin out. Sounds like there may be two wires reversed or something similar. Sounds logical that something would be out here since the socket at Jayco was successful.

Secondly as you have mentioned, check the negative/earthing connections on the car and the van and make sure that there isn't a floating (non-connected) negative. This could also be explained by the Jayco plug working as the socket would be wired with the negative in the plug. Note that some vans don't have an actual negative (earth) wire in the plug and use the frame as the return path.

There is some information off the Narva website HERE that you can reference plus plenty of other posts on the forum to assist.

Let us know how you go.

Cheers.