A/C and Furnace tripping the 3 amp fuse

[StevieD]

Hi. I’m looking for some help with this. I have a 1998 Sprinter. When I turn on the AC or Furnace nothing happens. When I switch the fan to “Hi”, I hear a click as the 3 amp fuse blows. I have looked at the AC on the roof top and there is no obvious fault or short. I have changed the thermostat and confirmed the wiring is proper and I have checked all thermostat wires for a short and all checked out good. Can anyone suggest where to go from here? Thanks in advance. Steve

[heikejohn]

3 amp fuse?
I don't know if that is correct for your AC, but all the fuses in our fuse box are 15 amp.
Check your owners manual.

[chuckster57]

Welcome to the forum!

Your talking about the 3A fuse in the thermostat right? I would start at the control box located in the return duct in the AC.

[StevieD]

Originally Posted by heikejohn

3 amp fuse?
I don't know if that is correct for your AC, but all the fuses in our fuse box are 15 amp.
Check your owners manual.

Thanks... it’s not the breaker. There is a 3 amp in line fuse in the control panel connected to the A/C unit.

[StevieD]

Originally Posted by chuckster57

Welcome to the forum!

Your talking about the 3A fuse in the thermostat right? I would start at the control box located in the return duct in the AC.

Hi. Its located in the circuit board beneath the A/C. It would protect the low voltage system. I just can’t figure out what is making it blow. I’m assuming that something is shorting out somewhere. Thanks