Voltage issue with Defender 110...?

Hi,
I'm running a 26 year old ex-mil defender 110. Following a bit of a refurb recently I've now got an 'A' bar with a couple of spots fitted. My problem is that when I try and turn the spots off after being on main beam they remain on and further checking has shown that there are 2.5volt (approx) remaining in the circuit after I turn them off which prevents the lights form going off when they should.

The relay/wiring for the spots are new and all other lights work as they should and I'm wondering where to begin the fault finding process with this one. I'm not electrics savvy in any way.

Cheers

I would start simple and begin with what was retro fitted who fitted the lights loom ..? And was a proper job done is the relay fully switching off and not holding slightly ... Are you useing a good body earth point for the lamps and the relay .. Haven't just found a earth wire and tapped into it ..? Pull the fuses for the system and see if you loose the 2v .. This may give a idea of. Where it is comeing from ....

Change the relay

Hi cheers for the replies. I had the relay changed and the earth looks good. Will look into it further and see what comes up,

ta ;-)