Without much specific info it's difficult to say very much. For starters; Halfords don't make sat navs. They just sell 'em
Is this a fitted in sat nav? In that case, is there a separate antenna that has maybe become disconnected or failed - or is it one stuck on the dash/windshield- in which case it may have just failed. You'll need to go rummaging round the back of the unit.
It it's a dash / screen mount item, it may be that the vehicle body is blocking too much signal, but I doubt that is the problem. It may just be worth trying a known good one in its place, just to be sure. You could also try your sat nav outside the vehicle as another double-check.
What is the make / model of the satnav?
It it's a dash / screen mount item, they are probably cheap enough simply to replace - you may be able to get a deal with lifetime map upgrades as well.
If its a buil=t-in item then tht may simply be far too expensive to replace. Just get a dash mount one.
X, August 2015
