Problem with chassis AC outside cooling fan's

jhanan · 07-18-2015, 11:29 AM

Hi, any know how to fix the outside cooling fan on the AC system. The inside AC works fine. I check the switch and all seems working find. The output is getting quite hot and heading to the heat exchange - where the heat exchange is also hot. But I cannot get the cooling fans to cycle on. They cycled last year - I could hear them come on and off.

I searched, but could not find a fuse.

Anyone know how to fix this?

2002 Horizon on FL XC chassis

Thanks.

Wizard · 07-18-2015, 05:42 PM

Not much information to go on but the fans are turned on by a pressure switch on the freon lines. Same with the ac compressor.

Possibility of low on freon

grtharris · 07-18-2015, 08:18 PM

jhanan, low Freon will keep them form coming on.

doublechevy · 07-18-2015, 08:33 PM

If the condenser is getting hot than the A/C compressor is working and the system should eventually shut down on high pressure. Check if you have 12 volts to the condenser plug connection. if 12V is present than you possibly have a bad condenser fan motor. the condenser fan usually cycles with the A/C compressor. Can not help with the location of a fuse.

DancinCampers · 07-18-2015, 08:35 PM

They will usually come on when ac max cool is selected. Usually a relay involved.

jhanan · 07-19-2015, 07:07 PM

Quote:

Originally Posted by grtharris

jhanan, low Freon will keep them form coming on.

I always keep freon with me and a pressure gage. I'm running about 28lbs. In the green. When I unplug the pressure switch on the hot side (2 yellow wires) - the unit shuts the comp off and the radiator cools off. I plug them in, the comp comes on and the rad gets hot....but not fan action.....

jhanan · 07-19-2015, 07:09 PM

Quote:

Originally Posted by doublechevy

If the condenser is getting hot than the A/C compressor is working and the system should eventually shut down on high pressure. Check if you have 12 volts to the condenser plug connection. if 12V is present than you possibly have a bad condenser fan motor. the condenser fan usually cycles with the A/C compressor. Can not help with the location of a fuse.

I cannot find any fuse, I guess I will have to find the power connection to the ac fans and see if they have power, then maybe the motors - but 2 motors go out the same time? Seems unlikely. I wonder if is the pressure switch?

jhanan · 07-19-2015, 07:11 PM

Quote:

Originally Posted by DancinCampers

They will usually come on when ac max cool is selected. Usually a relay involved.

Yes, was testing with max ac. There is a relay mounted to the outside of the unit under the hood - and this relay has the power that goes to the hot side pressure switch as well, so I got believe the relay is good - it has power out to the switch when on.

jhanan · 07-19-2015, 07:12 PM

Has anyone removed the fans? How do you get the grill open - seems all the screws/bolts are hidden back there.

ChasA · 07-20-2015, 07:46 AM

I think you should call Freightliner. 800 FTL HELP.

cbeierl · 07-20-2015, 01:37 PM

Quote:

Originally Posted by jhanan

Has anyone removed the fans? How do you get the grill open - seems all the screws/bolts are hidden back there.

The grill door is held closed with a few screws at the front and back. The rear ones should be accessible from underneath, the front ones once you open the compartment door in front of the grill door. Once the screws are removed the door will hinge up but will need to be supported with a broom handle or something, since it has no gas cylinders. (Btw, the door over the house A/C on the right rear works the same way.)