Blown fuse

[hoops318]

OK fuse drama

i own a 1999 Skoda octavia estate (110 diesel)

Last night after attempting to pull away with my caravan all rear lights refused to work. Initially they were on then stopped. On investigation there was water in rear light cluster so can only asuumed its blown a fuse.

My question

1.Is it a blown fuse?

2.Where is the fuse(Caravan or car fuse box)?

Not sure if it is linked but my car central locking remote is not working either.

Please help as i really want to go away with my van.

many thanks

richard

[rwbaldwin]

Are the car lights working?

Is that water in the caravan cluster or car cluster?

If not it's unlikely to be a fuse as the left and right are separate circuits with their own fuse. It's more likely to be an earth which is common to both.

If it's just the caravan and all the lights don't work, then check the common earth (pin 3 on a 12N or 13)

[hoops318]

Water was in RH rear light cluster of caravan

Oddly LH indicator worked on caravan but nothing else

Car lights work fine

Sorry to be stupid but can you explain pin 3 on a 12s or 13

Many thanks

[rwbaldwin]

Water was in RH rear light cluster of caravan

Oddly LH indicator worked on caravan but nothing else

Car lights work fine

Sorry to be stupid but can you explain pin 3 on a 12s or 13

Many thanks

The 12N is the 7-pin variant of the caravan socket. The newer sockets are 13-pin. The common earth for all the caravan exterior lights is on pin 3 of the either type of socket.

There will also be a bypass relay somewhere in the car and that could also be causing the problem.

Is there a box somewhere near/wired into the rear lights?

[hoops318]

ok so its 7 pin

Is pin 3 counted left to right

and how do i rectify the problem

I cannot see a box

would it of been a retro fit?

you say near the lights

I take it you mean the car lights

Many thanks

[rwbaldwin]

Here is the wiring diagram for the 12N http://www.western-towing.co.uk/acatalog/7pin_12N_Wiring.html

The bypass relay is usually wired into the rear lights on the car for a retrofit. If it's not there, then try following the cable from the caravan socket on the car.

[hoops318]

ok

so how do i detect a problem and how do i rectify it

Does it need cleaning for example or replacing

Many thanks

[rwbaldwin]

You'll need a multimeter. First thing you need to do is to confirm that the fault is not in the caravan wiring. Test the socket on the car using the diagram. Use the multimeter between earth and each of the other wires. If the socket is working OK then the fault is with the caravan wiring.

If the socket isn't working you need to follow the wiring until you find the bypass relay. Some bypass relays have a buzzer that sounds when you indicate. Check the 12V supply and earth to the bypass relay. If it doesn't have power, check upstream for a fuse.

Check continuity between the earth at the bypass relay and the earth pin on the caravan socket.

If the above is good then you have a faulty bypass relay.

[pikpilot]

My experience with glider trailers is that water gets into the trailer plug past the rubber grommet and electrolytic corrosion occurs where the cables enter the brass contacts.

Glider trailers are left outside on wet fields all year round so it is an extreme case but it is not unusual to find the the copper cables corroded to a point where they are high resistance but look OK at first glance.

If the car is giving the volts on the socket pins, then I suggest you open up the trailer plug and remove each wire in turn for a thorough examination.

Assemble everything again with a good overall coating of silicone grease or similar.

[hoops318]

ok problem fixed

Essentially found where the towing electrics had been attached to vehicle electric loom.

Tightened all connections and lo and behold one of the connections was loose

Now working fine

Thanks for everybodies help