Anyone experienced with fuel systems and fuel dispensers for C stores. A customer is having issues with alarm probe on their fuel monitoring system. The probe monitors fuel level but when 2 fuel grades are selected the probe goes into alarm but everything is working properly and for precautions they have replaced wiring and probes but still show alarm. The fuel monitoring equipment has been tested and show no problems so its suspected to be interfernce in wiring, The probe wiring and motor wiring are ran in separate conduits. The grpunds have all been checked for both LV at probes and HV for STPs. My question is how would you test for interference in a LV line?? i hope i explained the issue correctly. I am in a rush this morning.