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Topic: Condenser fan 1992 40' U280 (Read 642 times) previous topic - next topic

Condenser fan 1992 40' U280

Have a 1992 U280. Purchased a year ago last April. Salesman said "everything works except the trash compactor". Fell for that one. Anyhow, changed out both roof air units for 1500's. Need to get dash air working. Was only blowing defrost. No vacuum pump. Added pump. Blows through vents fine now. Condenser fans not working. Changed over to R134A. Went well. Anyone know of location of fan fuse? Not under bed. Compressor working..no leaks. Any help would be appreciated.

Re: Condenser fan 1992 40' U280

Reply #1 –
Just a guess here...I think I remember seeing some reference to the GV condenser fans having a relay or circuit breaker mounted up front somewhere on the firewall, in the vicinity of the condenser.  Have you tried tracing the power wires from the fans back as far as you can see them?

On a lot of newer coaches the condenser fans and the A/C compressor get power off the same relay (on the isolator panel at rear of coach), but my B-2126 wiring diagram (U280-U300) does not show this "dual" power connection at that relay.  Since your compressor is working but the fans are not, your fans are probably powered on a separate circuit.  The tricky part is finding it!

That's all I got.  Good luck!
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Condenser fan 1992 40' U280

Reply #2 –
Do you have the Foretravel books? Your wiring diagrams are in there. The fans are controlled off the high pressure switch on the liquid line up by the condenser. It probably has 4 wires coming out of it. 2 for compressor other 2 control fan. It should be the same as my 91 circuut.if you don't have to diagram When I get back in from trucking thus weekend I'll see if I can post it.
91 GV U300 Unihome 40' Build 3811
6V92TA Detroit

Re: Condenser fan 1992 40' U280

Reply #3 –
Stump,

I'm looking at my automotive wiring diagram (B-2126) and my 12V diagram (B-2037) and I can't find the circuit you are talking about.  I will also be very interested in seeing what you post.  I would think '91, '92 and '93 models would be wired pretty much the same, but perhaps not.
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Condenser fan 1992 40' U280

Reply #4 –
At least on the 1993 U240, the fan relay is accessed by opening the driver's side front access panel.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Condenser fan 1992 40' U280

Reply #5 –
Thanks to all. Will do more tracing after work tonight. There will be light at the end of the tunnel. Just hope it's not a train.

Re: Condenser fan 1992 40' U280

Reply #6 –
Quote from: wolfe10 –
At least on the 1993 U240, the fan relay is accessed by opening the driver's side front access panel.

Which should of had gas shocks !  ::)
1993 U-240 "La Villa Grande"..CAT 3116 w/ Pacbrake PRXB...Allison 3060 6-speed..
Previous: 1983 Airstream 310 turbo diesel, 1979 Airstream 280 turbo diesel
                                      Build # 4297
                                      PNW natives
                      Home base:  'Cactus Hug' (Ajo, Arizona)
                        DW Judy & Chet the wonder dog
                        Full-Timers 'Sailing the asphalt sea'

Re: Condenser fan 1992 40' U280

Reply #7 –
Quote from: mike leary –
Which should of had gas shocks !  ::)

Just flip it up/open.  It should stay that way unless recently modified.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Condenser fan 1992 40' U280

Reply #8 –
Chuck you should be able to see condenser fan motor on diagram. Wires to it should if memory serves me right go back to a relay. The relay should be activated by the pressure switch on liquid line from condenser. It might show something like binary or it might say trinary switch. I had to replace mine and went all through the schematic diagnosing my faulty switch. But I need to look at the diagram to be sure . It was over a year ago and not on top if my memory bank.I should be able to look at it sat morning having coffee.
91 GV U300 Unihome 40' Build 3811
6V92TA Detroit

Re: Condenser fan 1992 40' U280

Reply #9 –
Quote from: wolfe10 –
It should stay that way unless recently modified.
At least until a big gust of wind comes along, and SLAMS it down on the back of your head!  Been there - done that.  :'(
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"
 

Re: Condenser fan 1992 40' U280

Reply #10 –
I was mistaken thinking i had seen a schematic on the condenser fan wiring.
if yours is like mine You will see a high pressure switch up front on the condenser line. It will have 4 wires coming out of it. Look at first picture. I had to replace mine and Foretravel sent an adaptor harness to connect to coach harness. Which by the way was not wired correctly and I had to figure that out,another story.
On the driver side of the condenser is another electric connection as seen in pic 2.
To test fans: Turn on Ignition switch, and a/c Inside blower on low, push compressor switch. Unplug the 4 wire connector that is going to the switch. On mine there are 2 blue wires and a green wire and a black wire. The fans are turned on by the green wire making a ground. Take a jumper wire or you can use a test light,and ground the green wire. Fans should turn on. If they do, More than likely you have a bad pressure switch. check the black for continuity to ground. Power to the fans comes down from somewhere up in the dash and plugs into the other plug on the front of the fans. The relay sounds  like it's built into the fan assembly on mine. I can hear them click and energize when I ground the green wire. The 2 blue wires carry power to the compressor circuit and should show continuity through the switch.
91 GV U300 Unihome 40' Build 3811
6V92TA Detroit