Combines Hot A C fan switch one to look at

Rolf we have used relays and the compressor clutch has its own power wire but it still shuts down under hot days, works perfect at night. It seems to be worse on R72s'. The local air con man say's he has the answer now after refitting a few combines with rotary compressors they don't play up at all

G'Day Johnboy Yea, we've have had our drama's with our A_C as well!! last year we got a new TX valve installed up under the cab at the Evaporator and boy did that make a difference!! I don't think it has work as well since new plus moving the compressor away from the engine and now I have "hopefully" getting a bit more air flow out of the vents it should work a lot better. It all come's down to the compressors cylinder head pressure, the hotter it is the higher the Cylinder head pressure the hotter everything run and so around you go!!!!! some day's I have tuned the AC off for awhile just to let me know that it really is working and it gives it a bit of a break and usually find it runs a bit better after. Also fine that if I take one of those trigger spray bottles with and spray some water around in the cab it seems to help with cooling!! or so it seems to me!!!!

Rolf I appreciate your occasional input to this forum. My Agco mechanic told me that there is a relay kit for helping to improve the mediocre air flow in the cab. It sounded pricey so I was planning on doing it myself with a heavy duty off-the-shelf relay. I was originally thinking of only installing one relay for the high speed setting, figuring that it was the main reason for the switch heating. My question is did you check amperage draw on each of the three fan speed settings and if so what were theyIJ

G'Day Gamaman I have just used bosch 30 amp automotive relays up under he cab near the brake master peddles. I have not taken any current readings I have taken the main power for the relays from the main power relay up in the cab console and I have a 30 amp fuse in line down to the relays and the fan switch up the top is used to turn the relays on and it uses the original power supply power but with a 5 amp fuse instead of the original 30 amp fuse. I will take some pictures of what I have and they to get them on to the mod site. Rolf

Just to clarify At the back of the ops manual there is a wiring diagram that will show that the switch in the cab supplies power down to the fan for each position 1,2 and 3 also the switch supply's power down to the AC clutch at the back of the machine. Each coloured wire down to the fan is for each fan speed, what I have done is spliced a relay into each (speed) wire down under the cab and run a separate power wire down to the relays, I then use the coloured wire from the switch up top to turn the app orate relay on, this in turn switches the relay on which sends good clean power to the fan from the relay. were you mount the relays is up to you! I did it under the cab for convince and so if I have any troubles I can get out and fix it easy. Hope I have made sense!!!!! If you take your ops manual into a auto elect he should be able to shown you how it can be done! just make sure that you grind away some paint were you mount the relays as you can make a loop of wire from the one side of the relay (coil) up to were you mount it to make a good ground!!! Rolf