3515CH HVAC

[denjen]

Trying to troubleshoot an HVAC problem. I have been through what service manuals I could find; but I can't find anything in them related to HVAC. I did see that the 20 series service manual has section in it for HVAC. Mine is tier 4 and does not have a dryer.

My initial problem was no cold air and I noticed the compressor clutch was not engaging. I shut tractor off and reseated the connector going into the compressor and it appeared to work and this lasted for about a month. It then happened again and reseating didn't work. Since under warranty the dealer came out and said had to replace the compressor and condenser, well he came out and replaced them, pulled a vacuum for about an 1 hr and filled with 1.6 lbs (per what Branson told him).

Fired up and clutch still wouldn't engage. After trying multiple things he said would send me a control module to try, which didn't work. They said they would need to bring into the shop to work on it.

I have very limited HVAC knowledge; but have started trying to track down the issue which to me is seems it was probably electrical. So far I have tested to make sure the compressor clutch engages and it does. I checked voltage on the sensor that plugs into the new condenser which it has and I tried to bypass the sensor by shunting it with a wire and didn't help

I am going to next trace the condenser wire back up to the dash and try to check it's continuity.

I know I am missing it; but I can't find a HVAC fuse anywhere. Does anybody have a service manual for cab version? The dealer didn't have a service manual for cab.

Any other thoughts would be appreciated. Dealer did say he was dropping off a tractor near me this weekend and could swing by and pick it up, which I might do if needed.

Thanks for reading and any suggestions.

 

[LouNY]

Maybe I'm missing something,
is the compressor clutch engaging when you turn the AC on?
If the compressor is running with the AC on and not cooling I'd check the system pressure with it running.
If the clutch is not engaging and running the compressor then I would check for voltage to the compressor when the AC switch is turned on.
If the compressor is working and the system pressures are correct then it's time to see if the control louvers are working in the cap,
you could also pinch off the heater hose going to the cab and see if that helps.

 

[Cougsfan]

Not sure why the service guy would have replaced the condenser. There isn't much mechanical or electrical going on there that could cause a problem (unless the fins were clogged).

Rather than filling the system with a fixed amount of refrigerant, he should have been using gauges and filled it until the pressures on both the suction and pressure sides of the compressor were to the factory recommended settings. If he charged the system without using using gauges, or with the engine not running and/or the clutch not working; there is no way he could have verified that it was charged correctly. In fact if he indeed did what you described, it would make me question if that service man is qualified to charge an ac system.

I am confused from your write up if the clutch is engaging or not. You can just look at the clutch to see if it is engaging when you turn on the AC system. If it is not, Lou is correct in suggesting to check to see the clutch is getting power when the ac is set to cool. If it is, it is a bad clutch, if it isn't, you have a control issue that needs resolved.

Mine doesn't have a dryer either (even though the manual shows one installed). That bothered me when I first found it out, but my AC (which had its own problem with a leaky hose that needed resolved) has been working fine without a dryer, but requires special attention to moisture removal. No dryer means pulling a vacuum and holding it prior to charging is critical and essential to remove any and all moisture from the system. An hour is a fairly short time to hold the vacuum. I would recommend holding a vacuum overnight. If there is any moisture in the system at all, it will turn into a drop of ice in the expansion valve and prevent the AC system from working (I learned this from the school of hard knocks). A way to tell if moisture is the problem is if the system cools for a while when you first strat it up, then stops cooling.

The other reason I mention the dryer, is because without it, my system holds a somewhat less refrigerant that what is mentioned in the manual for my particular tractor. Your problem may simply be it has too much refrigerant in it.

If you have one, I'd suggest using an infrared thermometer pointed at your cooling air duct in the cab to quantify how well the system is or isn't working. But any thermometer will work.

The 20 series manual is fairly complete and useful in describing troubleshooting and servicing, and it is not much different than it is with any automotive type of refrigeration system.

 

[denjen]

Sorry for any confusion, the initial symptom was the clutch didn't engage, I reseated the compressor connector and it worked for about a month and stopped. The dealer decided to replace the compressor and condenser. I asked why replace the condenser and they said that is what Branson said to do....

After replacing both and drawing a vacuum for an hr, fired up the tractor and clutch never engaged. He didn't have a volt meter and mine was not working, he tried to hook up the tank after many hours he said it had the required amount (Branson said 1.6 lbs). He didn't have service manual for the 3515CH that included AC.

I have looked at the 20 series service manual to try and figure it out, the compressor is not getting any voltage (at least I got new volt meter). I tried to trace the compressor wire back to see if there is an electrical issue; but w/o a schematic I was basically shooting in the dark. Now, there is a sensor on the condenser which I thought could be high pressure sensor and it does have voltage on the leads. I asked him where the low pressure sensor is and he said there is not one and the condenser sensor worked for both low and high pressure.

The dealer delivered a tractor near me Sat so they have picked it up.

I won't disagree about qualification. I will update when hear something.

Thanks for the help and if anybody knows of a 15 series cab with AC service manual that would be great.

 

[ptsg]

Thanks for the help and if anybody knows of a 15 series cab with AC service manual that would be great.

I don't think we even got a service manual for the cabbed 15 series. However, I would expect them to use pretty much the same HVAC stuff across all the different series, 15, 20 and 25 (discontinued) series.

 

[denjen]

I will post if I find one.

 

[denjen]

Sorry about the delay. The dealer finally got a service manual from Branson and it appears the evaporator sensor is bad, Branson is telling him per warranty can't replace the sensor must replace the whole HVAC component in the roof.

I did verify with a different dealer that Branson does require the compressor and condenser to be replaced at same time, at least for warranty.

 

[Asteral]

Sorry for any confusion, the initial symptom was the clutch didn't engage, I reseated the compressor connector and it worked for about a month and stopped. The dealer decided to replace the compressor and condenser. I asked why replace the condenser and they said that is what Branson said to do....

After replacing both and drawing a vacuum for an hr, fired up the tractor and clutch never engaged. He didn't have a volt meter and mine was not working, he tried to hook up the tank after many hours he said it had the required amount (Branson said 1.6 lbs). He didn't have service manual for the 3515CH that included AC.

I have looked at the 20 series service manual to try and figure it out, the compressor is not getting any voltage (at least I got new volt meter). I tried to trace the compressor wire back to see if there is an electrical issue; but w/o a schematic I was basically shooting in the dark. Now, there is a sensor on the condenser which I thought could be high pressure sensor and it does have voltage on the leads. I asked him where the low pressure sensor is and he said there is not one and the condenser sensor worked for both low and high pressure.

The dealer delivered a tractor near me Sat so they have picked it up.

I won't disagree about qualification. I will update when hear something.

Thanks for the help and if anybody knows of a 15 series cab with AC service manual that would be great.

Denjen i posted the new updated 15 series service manual last week this will include your model and all 15series cabs and should have a pretty through section on your hvac

hahah nvm i should read more of the page before responding sometimes i didnt see your post about them getting the manual lol