Message Forums

We have been towing for two years now but recently changed our caravan.  As soon as we towed our new one we noticed that the caravan headlights come on under braking.  You can see the front marker lights in the mirror!  The front marker lights on our old caravan never worked so I don't know if this happened before.

Is this likely to be a fault with the caravan wiring, or with the tow bar wiring or is it actually perfectly normal?

It could be an earth fault or a short, it would be worth checking the connections in the plug and the socket on the car, also check earth connection is good-clean and tight.

The supply to the van comes from the car, have you checked that all the lights are working correctly on the car?

Hi, yes the car is working ok on its own.

Hubby is going to get his multimeter on it this evening and see if we can trace where it is going wrong.

Quote: Originally posted by 664DaveS on 07/8/2007

---

It could be an earth fault or a short, it would be worth checking the connections in the plug and the socket on the car, also check earth connection is good-clean and tight.

---

These earth faults that Dave has mentioned must account for the majority of lighting faults on both trailers and tow cars.

Caravans in particular use many weak earth points.

Anybody who uses several trailers as I do would do well to consider investing in a socker tester similar to this one on Ebay:

http://rover.ebay.com/rover/1/710-5232-2978-1/1?AID=9479574&PID=1428744&mpre=http://cgi.ebay.co.uk/NEW-CARAVAN-TRAILER-TOWING-ELECTRICS-SOCKET-TESTER_W0QQitemZ110154763580QQihZ001QQcategoryZ36632QQssPageNameZWDVWQQrdZ1QQcmdZViewItem