Since I changed the A/C compressor I appear to have a problem with the Cooling fan being on whenever the ignition is on. When I turn it off the fan continues for about 5 seconds.
Did a check on the OBD all ok no DTCs oil and water temps around 50C, Transmission oil also. The OBD shows 11% fan speed with heating on, with A/C on cooling fan is 55%.
But actually the speed does not change appears to be about max. Just a thought, Maybe I should try disconnecting the battery again and doing the reset etc. OK Checked that so hopefully it is the connector or a wire that got stressed while removing the Fan/Shroud. Any other ideas more than welcome.

 

Do you mean the fan runs whenever the engine is actually running? Or any time the key is in the Run position, regardless if the engine is running or not?

I wonder if some of the behavior you've noted is normal. IIRC, with the engine running, the fan always runs. The fan speed depends on the cooling requirements. The fan speed increases with the AC system in operation, because extra airflow is needed through the condenser (and the radiator to some extent). Don't quote me on this, but I thought AC high side pressure is one of the inputs used to determine fan speed. Increased airflow helps keep the refrigerant pressure from getting too high. Because your old compressor couldn't build much pressure, perhaps the (normal) higher fan speed was never commanded. Now that the refrigerant pressure is back where it belongs, the fan may be responding normally as designed and you don't actually have a problem.

 

The fan runs in the ignition on position Motor off and cold, Ok I have gone over the circuit diagram and have an understanding of the system I hope !
I can switch off the A/C and put it on heating, the fan does not change, My analyser says that the fan is almost off 11% switch on cooling, no change in fan speed, Analyser says Fan speed 55%. The controller is integrated with the Fan motor ! There are basically 4 connections Chassis -Ve, +12V for the controller, +12V for the Fan (via the Controller) and a PWM signal at 140Hz that controls the speed of the fan. If this is high +(5V) the fan operates at max, as the negative going pulses get wider so the Fan goes slower. In my case the PWM line on FH108_1 remains high on the fan side of the controller so the fan operates immediately that it gets the 12v, switching off the ignition this remains high for a short period and then goes off. It appears that the PWM line White / blue wire is not connected from the Engine ECM to the White Blue wire going to the controller, 3 options-
1. Connector does not make good contact
2. Wires White / blue are broken somewhere
3. Controller is US., Hard to believe as it was working perfectly before.
No idea what is in the controller apart from a few FETs, should not have failed while being removed no volts on system.
Most likely wiring or connector fault.
Hopefully the weather will be ok................................................
Cheers Mike

 

CAUSE - DIRTY CONTACTS ON CONTROL LINE CONNECTOR,
Phew lucky !! Got at the plug and skt opened them and sprayed both parts with contact cleaner, a few in and outs and put them back together. Ign on no fan, Started A/C off A/C on fan is A OK. turn off and fan stops almost immediately.Put a couple of tie wraps in place to hold the connectors together tightly. Went for a 30K drive with A/C on, OK. One thing I noticed before when the fan was running at max revs even after 20K at 25C outside the temp gauge did not go above 3/8 scale so it really was keeping the coolant temp down.
I have noticed on different forums the problem with the fan running at max and not turning off when the ignition is switched off. Fitting a new fan motor / controller fixed the problem.
Probably it was not the controller just a bit of oxidisation of the contacts at the plug /skt and fitting a new one cleaned the contacts. This is a very low current PWM signal and it is easy for contact resistance to be a problem.
The DCCV PWM drive uses quite a high current so it is much less of a problem although it still happens. (Gold contacts are good and reed relays are mercury wetted for low currents)
Still Purring
Mike
Ps. Anyone want to send me a duff controller/ motor and I will strip it down and find the problem. Full description of fault is also preferred to save time. Please note I have never opened a combined controller module so no promises but pure interest!!

 

Very nice work