Dash Air Condenser Fan Not Running

[trailmug]

2008 Signature, I've done extensive work on the dash a/c system over the years, but have yet to run into this.. no power to the condenser electric fan when the compressor is engaged. Goes off on high head when parked (obviously, thanks binary switch). This one doesn't have a switch-controlled fan, so I presume it gets its power from either a discrete power relay or the chassis multiplex unit or fuse box in the front pass-through bay. I always assumed it ran off of the clutch relay, but apparently not. Having trouble finding the condenser fan circuit on the wiring diagrams. The cable does appear to go to the front cargo bay, but I thought I'd reach out and see if anybody had knowledge of how it gets power.

Thanks,
Rob

[vito.a]

On both of my coaches the dash A/C dryer is located up front next to the generator.  The 4-seasons dryer has the binary switch installed in the top of the dryer.  

[trailmug]

Switch is working OK since the clutch gets power.. thinking there's a relay, fuse, or solid state relay in the mix somewhere that needs attention.

[myrontruex]

I know the Signature is a far different beast than my Endeavor a 2008, but I imagine the AC systems may be close. Do you have a panel below the driver in the outside compartment?

If so, there are some small relays in there and a fuse as well. I have diagrams and notes in case you have something similar. 

[Frank McElroy]

On 10/31/2023 at 2:59 PM, trailmug said:

2008 Signature, I've done extensive work on the dash a/c system over the years, but have yet to run into this.. no power to the condenser electric fan when the compressor is engaged. Goes off on high head when parked (obviously, thanks binary switch). This one doesn't have a switch-controlled fan, so I presume it gets its power from either a discrete power relay or the chassis multiplex unit or fuse box in the front pass-through bay. I always assumed it ran off of the clutch relay, but apparently not. Having trouble finding the condenser fan circuit on the wiring diagrams. The cable does appear to go to the front cargo bay, but I thought I'd reach out and see if anybody had knowledge of how it gets power.

Thanks,
Rob

This fan is powered from the rear Kongsberg CCM located in the ceiling of the first bay behind the steer axle.  The panel between the frame rails will need to be removed to gain access.  Open the black CCM cover and the 30 amp fuse F2 and relay K3 are for the condenser fan motor.  Most times this motor goes bad and pops the fuse.

[trailmug]

Thanks, exactly what I needed. I was worried it would be one of the solid state outputs on the Kongsberg like the big boy boost switch which blew, I assume due to inadequate diode protection. I can live without the batt boost, but not the condenser fan. 😁

[Frank McElroy]

In case you don't have them, here is a link to a set of wiring diagrams for your coach.  To get the option to download all pages in one file click on the title (not download) in the link below.

 

1 hour ago, trailmug said:

Thanks, exactly what I needed. I was worried it would be one of the solid state outputs on the Kongsberg like the big boy boost switch which blew, I assume due to inadequate diode protection. I can live without the batt boost, but not the condenser fan. 😁

The battery boost switch not working is likely due to a failure of a component on PCB #6 in the rear run bay.  I've seen this a number of times on your model year coach.

This board has the remote battery boost and salesman switches on it.  The led lights on the board will help identify the problem.