Hello all, I recently purchased a d5h lgp. It has air conditioning that was partially disassembled, broken lines, missing harnesses, etc... I've since replaced parts like the condenser, dryer, accumulator, and condenser fan wiring harness. I put everything together, put a vacuum on the system for a while, added refrigerant and after some fiddling and figuring out, I got the ac to blow pretty cold. I'm making progress. Right now I'm waiting on a Deutsch connector that was accidentally not shipped to me for one of the two condenser fans. The other condenser fan is installed and plugged in. Ok so here's my question, up in the condenser group box there is a relay wired into the factory harness. I bought and installed factory cat harness and relay. When I kick on the ac inside the cab it sends 24v to the condenser fan harness all the way to the relay. The relay clicks like it's working but doesn't send any power to the leg that supplies the fans with power. I've tried 3 relays, they all click like their energizing that leg but the leg gets no voltage. When I remove the relay and stick a jumper wire from the hot (which becomes energized when you turn the ac switch on on the dash like it should) to the leg that supplies the fans with power, the fan clicks on and works as it should. When I switch the dash temp control to the heater side, the condenser fans turn off as they should. Am I missing something here? Why does that relay need to be there if the switch behind the dash supplies power to the fans only when on the AC side and only when the AC is on just like it should? Some of this model of dozers had a dryer with pressure switch up in the condenser group box. Mine does not. It has the drier with quick disconnect fitting up on top of the radiator and it's like that from the factory. Maybe the relay is there to accommodate other serial numbers that had the pressure switch up in the condenser group? My pressure switch is on the compressor itself and is a switch that works as a low pressure and high pressure cut out for the compressor. If everything works as I think it should, is there any harm to bypassing that relay? When I bought the dozer that relay had been cut out and spliced around and the fan wiring was all ghetto spliced. I fixed it to be factory again and would like the relay to work as it should but from what I see, the relay serves no purpose and no matter what I do, won't provide voltage to the fans hot leg. My manual schematic shows a fuse for the condenser fans but I have checked every fuse I can find on this machine and they're all fine. Does anyone know if there's an inline fuse I'm missing somewhere? Maybe when they switched these dozers from r12 to r134a they added an inline fuse that I can't seem to find? Anyone have experience with that relay up on the condenser box or see any issue with bypassing it? It's a 5 prong relay. The middle prong is empty. There's the ground prong, hot prong that becomes hot when ac dash switch is turned on, the prong that goes to the condenser fans then another mystery prong that just dead ends in the wiring harness somewhere, which according to my schematic would normally go to the pressure switch up by the condenser if it were equipped with that. Any insight is much appreciated! I know there is some wisdom on here that can help. For now, I think I'll bypass the relay if everything is going to work how it should with it bypassed...unless someone sees an issue with that. Thanks for all your time! -Mark
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