Cooling fan - A/C question

[10-1=9]

Our trucks have a 2 speed hydrolic fan powered by the power steering pump. When the A/C compresser is turning will the fan run on low or high speed? The fan turns but hardly moves any air. The shop tells me the high pressure cut out switch is turning the compressor off. Now they are trying to determine if it's mechanical or electrical. Everything seems to be pointing to the ECM not sending a signal for high speed fan. The motor does seem to run a little bit hot but The engine is new and this is the first time I drove the truck in about 3 months so I'm trying to remember how everything was. The stock P/S lines were just replaced with a braided kit (because of leak). I don't necessarily think this had anything to do with it. The steering works perfect so I think all the air is out of the system. Can the rack work but the fan still be air bound? Think anyone help me out?

 

[10-1=9]

Can some one please go out to the truck and see if the fan turns on when the AC compressor cycles? If so is it moving a lot of air?

 

[ARRESTmeRed04]

Can some one please go out to the truck and see if the fan turns on when the AC compressor cycles? If so is it moving a lot of air?

Tried it on the car, truck is at the alignment shop, and fan stays on low. I let it idle up to temp and the fan never kicked up to high speed

 

[Ironhead]

Fan will not kick into to high unless temps get over set point for a predetermined time by ecm. This can be adjusted by a good tuner .
Unless you are seeing temp way over 210 to 220 on a stock tune it will always be low speed .The speed of fan is adjusted through a coil that proportions the flow of oil ,it is not a high or low voltage switch .The voltage to coil is increased allowing the valve to open to let more flow through

 

[Ironhead]

Just because a/c is on does not determine whether the fan is on high or low.

 

[VENOMOUS1 RACING]

You can very much have air in your lines as well as when replacing lines fan module drains fluid.

 

[Final GTS]

The Hydraulic Fan IS NOT A TWO SPEED. It technically has well over 100 speeds, and is Duty Cycle controlled.

The fan does NOT kick to "High" when the A/C turns on like the Electric Fan cars. The fan will remain Duty Cycle controlled with the same fan target, but with a slightly altered routine. Fan speed is directly proportional to the difference between fan target temp and actual temp.

 

[10-1=9]

We'll thanks for the input. It gives me a better idea what's going on. So the fan can be air bound but have the P/S work ok then?

 

[10-1=9]

Fan will not kick into to high unless temps get over set point for a predetermined time by ecm. This can be adjusted by a good tuner .
Unless you are seeing temp way over 210 to 220 on a stock tune it will always be low speed .The speed of fan is adjusted through a coil that proportions the flow of oil ,it is not a high or low voltage switch .The voltage to coil is increased allowing the valve to open to let more flow through

Thank you! " if I had some info by 9:30 I might actually slept last night"

 

[Ironhead]

We'll thanks for the input. It gives me a better idea what's going on. So the fan can be air bound but have the P/S work ok then?

If your fan is running on low speed and the engine is not overheating then your fine .
What is your temps once it is warmed up????

 

[ARRESTmeRed04]

The Hydraulic Fan IS NOT A TWO SPEED. It technically has well over 100 speeds, and is Duty Cycle controlled.

The fan does NOT kick to "High" when the A/C turns on like the Electric Fan cars. The fan will remain Duty Cycle controlled with the same fan target, but with a slightly altered routine. Fan speed is directly proportional to the difference between fan target temp and actual temp.

Is there anyway to alter that in the ECM? The A/C in my viper sucks at a stoplight but works well on the highway. Perhaps a bump in fan speed pulling more air over the condenser would help at traffic lights. Compressor doesn't cycle on and off repeatedly like it's low on Freon.

 

[Ironhead]

Is there anyway to alter that in the ECM? The A/C in my viper sucks at a stoplight but works well on the highway. Perhaps a bump in fan speed pulling more air over the condenser would help at traffic lights. Compressor doesn't cycle on and off repeatedly like it's low on Freon.

sounds like compressor is getting weak on low rpm.could put a small electric fan on it

 

[10-1=9]

If your fan is running on low speed and the engine is not overheating then your fine .
What is your temps once it is warmed up????

Most of the time water temp is 1/2 or just to the right of it. At one point it jumped to past 3/4 but came down and after I turned the heat on full. Oil temp was just above 200 Deg. It's a new engine so I don't know if it will run exactly the same temp is the old one. After what I paid for the rebuild im taking no chances on overheating this engine. The main problem is the A/C not working. They are telling me that the head pressure is to high & kicking off the compressor. They believe it's due to not enough air flow across the condenser. They believe the fan is not turning on high enough to keep this from happening The wiring & the ECM were sent along with the motor for rebuilding. From what I understand my ECM and wiring harness was used to run the rebuilt motor on the Dyno. They were going to reflash or tune the ECM before returning it to me. We are thinking maybe it's a glitch in their programming. Any help would be appreciated

 

[ARRESTmeRed04]

Who did the rebuild

 

[Ironhead]

Most of the time water temp is 1/2 or just to the right of it. At one point it jumped to past 3/4 but came down and after I turned the heat on full. Oil temp was just above 200 Deg. It's a new engine so I don't know if it will run exactly the same temp is the old one. After what I paid for the rebuild im taking no chances on overheating this engine. The main problem is the A/C not working. They are telling me that the head pressure is to high & kicking off the compressor. They believe it's due to not enough air flow across the condenser. They believe the fan is not turning on high enough to keep this from happening The wiring & the ECM were sent along with the motor for rebuilding. From what I understand my ECM and wiring harness was used to run the rebuilt motor on the Dyno. They were going to reflash or tune the ECM before returning it to me. We are thinking maybe it's a glitch in their programming. Any help would be appreciated

Well then there is one way to check the high head pressure then .Get a good size fan and put it in front of condenser and turn on a/c..If it is a lack of cooling it will let a/c work
If it never works then they screwed the pooch doing something.Just sounds like they are just making shit up as they go with excuses

 

[10-1=9]

Arrow Raceing Engines in Auburn Hills MI. Forged/H beam bottom end with a cam. Stock intake/exhaust manifolds, new right head, front cover/oil pump, oil cooler, flash ECM, fly wheel, t bearing, clutch assy, JMB A/C & breather. Mid pipes. Braided P/S lines. Took it on a 15 mile shake down run that felt GOOD! As soon as I get my A/C working and make up a better heater hose bracket I should be like Mini Mo "good to go"

 

[10-1=9]

Well then there is one way to check the high head pressure then .Get a good size fan and put it in front of condenser and turn on a/c..If it is a lack of cooling it will let a/c work
If it never works then they screwed the pooch doing something.Just sounds like they are just making shit up as they go with excuses

That's exactly the same thing I was thinking. Spoke to the shop owner and longtime friend this morning about it. He didn't get started on it until Fri afternoon so they were in the middle of it when quitting time came. Their tech will get back on it Monday morning. He believes that the fan was tried and it worked okay. I'm going over Monday morning to see what was tested and what was not. I'll let you know what I we come up with. Thanks for the input.

 

[Ironhead]

So arrow built it and someone else installed it.

 

[10-1=9]

The shop pulled it then dressed it to Arrow specs. Arrow sent a crate to return the engine in. The complete engine, wiring harness, ECM went minus the exhaust manifolds & clutch. When they received it was torn down the check for damage. It was rebuilt to my specs then dyno checked with my components. After it was returned the shop reinstalled everything and put it back in the truck. Everything pretty much went as planned except for the power steering pressure line leak coming out of the pump and air conditioning not working.

 

[10-1=9]

Seen your truck in the garage, looks pretty sweet! I swore I would never buy another white vehicle but then again that does have BLUE stripes on it. So I would definitely make an exception