IDS Active Command Fan speed

[ktmlew]

How much delay should there be when running the duty cycle up? Have an A/C issue. 39* at idle 53 on the road. When in bay with machine connected LS 25-30 HS 170-280. Raise RPM to 2200 and LS cycles 20-50 but HS will sometimes go past 350. Eventually fan WILL come on but duct temp has gone way up by then. from 39-50ish. If you get the fan speed up, still indicates "low speed", HS stays down in the 170 range and cools better. Has aftermarket aluminum radiator, tuner, etc.

[ktmlew]

Finally found the pinpoint test. Above 2800 fan rpm @ 2500 engine rpm at 100% duty cycle. Delay is normal.

[tonybullitt]

fan clutch are very delayed

[ktmlew]

Any ideas on reduced AC performance at road speed. More than 10 degrees temp increase from idle. 40* @ idle to 49*-52* at cruise speed.

[8WA Sman]

I am thinking blockage. Do you have a refrigerant identifier?

[ktmlew]

No identifer. Boss replaced orifice tube. But he has been known to install them backward. He started off chasing empty system. Was leaking at Shrader valve's. Think it may still have a leak. Tried locating with black light but nothing found. Truck has pretty blue anodized block off plates all over engine. Need to see what ECT is at.

[mchan68]

Evaporator to condenser line.

[Keith Browning]

Also make sure the charge is correct. I recently had a Transit doing the same thing and I realized I mistakenly thought it had reat air and put too much refrigerant in it. I am sure this is not the case but you never know.

[cbriggs]

How is the airflow from the vents? Lack of airflow accross the evap core can make high side go very high. Possibly a dirt or desbris plugged evaporator core?

[ktmlew]

How is the airflow from the vents? Lack of airflow accross the evap core can make high side go very high. Possibly a dirt or desbris plugged evaporator core?

Evaporator is clean. Ended up overcharging it by 4 oz. 40ish @ idle/46-47 at cruise. I suspect the AC machine needs scales calibrated.