2005 Vauxhall Zafira front indicators

i have an intermittent problem on my zafira. it does not matter whatever the weather is, rain or shine makes no difference.the problem is the front indicators are working fine then the warning comes on the dash saying theres a problem with the indicators, the front ones have stopped working the rear ones are ok but turning on the four way the front ones work or locking with the key fob they work also. i've asked a mechanic about it, he dosen't think it's the relay as that effects all the indicators. help!!!