turn signal and flashers

guys a few days ago i set (dump truck) about 2hrs with the flashers on then i notice that they was not working,check to see if they had just turn off or something and they was still in the on position..i fig. they just got hot so i let them cool and tried them again and nothing...now whaen i turn the signal light on left or right the flashers come on and no trun signal,if i trun the falsher on it works just fine...i replace the relay but have not found the flasher itself came someone tell me where it should be..1997 freightliner and would the flasher going bad cause something like this???i need to get this fixed working at night on the interstate came be very bad....

 

thanks for the info

 

hay i just went out and looked under the dash and i traced the wires from the switch as far as i could and didnt find anything..i thought i could hear it while blinking but only thing i hear are the relay thats powering it and i feel it ...i took the bottom of the dash out and the gauge panel on the left side....its a fld 1997 if that makes any diff. thanks