hi i have a merc sprinter 308D 98 model, my heater plugs are not working due to the relay. ive tested the heater plugs and they are fine, ive put the ignision on and tested the wire and ive got no power, once the van is started it runs all day unless left for a while. I now dont no where the relay is so i can change it. please need to no where it is as its my bread and butter

Den, August 2010