Help - how do I test for continuity / earth on a trailer with a multimeter ?

[Mike123]

Have a trailer plug -Euro 8 pin type, which when you move the plug the rear light goes on and off.

Assume that we have a loose wire / bad earth - but how do I test it given I can't connect both ends due to the length of the cables ?

Any help would be great

 

[Bobbydaisy]

This is a very basic check for continuity.
Use a multimeter , most have a buzzer function ( usually shared with resistance , ohms) put the red and black leads together a buzzer will beep. Get a length of wire long enough to reach both ends of the cable , plug/ socket circuit you want to test . Put the red wire onto the pin /terminal/ cable end you want to check , black wire onto croc clip onto one end of the long wire , and other end of long wire onto the pin at the far end you want to check for continuity, buzzer will sound if you have continuity, if not then open circuit. Check each pin to earth for a short circuit.

Like I said a very basic test only for continuity.