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Old 17th November 2019, 21:01   #31
marinabrian
 
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I would suggest that the chart applies to the 2 speed resistor fans as well since the control software is within the ECM and it cannot "know" which type of fan is plugged in, particularly as 2 and 3 speed fans were fitted to cars in an apparently random fashion up until the end of production.

Simon
I shall clarify a couple of points if I may Simon, in the interest of preventing confusion.

There is a facility within the SA string of ZCS coding to differentiate between there being a two or three speed fan fitted, and the PWM output of the ECM is adjusted accordingly to which type is fitted

Two speed fans were fitted to all cars of 4D model years from VIN 324474, anything else was not originally fitted at the factory.

Brian
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Old 18th November 2019, 08:38   #32
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There is a facility within the SA string of ZCS coding to differentiate between there being a two or three speed fan fitted, and the PWM output of the ECM is adjusted accordingly ...
We are talking about the KV6 here not the diesel so I'm not sure where a "PWM output" comes into it.

Could you please tell us exactly how the fan control is modified following these coding changes for both KV6 and diesel ECM. Without that information we are no further forward.

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Old 19th November 2019, 11:52   #33
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Could somebody provide me with MGR instructions to fill and bleed the cooling system? Thanks.
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Old 19th November 2019, 18:02   #34
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Poor flow through the heater won't cause high coolant temperature Alan.

Dave's fan has two speeds, as he states in the post you've quoted.

Simon


Simon you are quite correct but the control circuit has three, and it can not know what fan is fitted, what happens is the slow and medium speeds become speed 1 and the high speed remains the same. Hence the need for a resistor heat sink on the wiring.
So the three speed protocols still apply.
As to the possible poor water flow you are correct it would not cause a high coolant temp but it could cause the poor heat transfer on the passenger footwell.
The only way to check the possible overheating would be to run the engine and take digital temperatures of the coolant temp.
Then remove the engine thermostat and see what the difference in the graphs are on the same protocols used with the stat in place.
This will allow to determine if the engine is running hot or not or if a sensor is off. You can buy adhesive colour strips in 5 degree and 10 degree increments. These small inexpensive strips are often used in CHP units worldwide and also in motor sport. There great for a reference check.
Hope this info helps any confusion I caused.
Basically the fan runs at two speeds but the car thinks it has three.
Which is one of the reasons we fit heat sink resistors to protect the fan.
Alan



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Old 19th November 2019, 18:24   #35
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Hi all. Over recent months I have had new belts, thermostat, water pump, 2 speed fan and radiator. Temp is rising to 110 in stop start traffic before high speed fan brings it down. Operates at 92-97 in free flowing traffic. Getting cool air in passenger footwell and hot in drivers. Any idea what could be causing 110 operating temp and is this a problem?


Just thought I would bring Dave’s original post back into the thread. Then make a Statment I have made many times. Just because a thermostat is new does not mean it is working properly. It is just a tin full of paraffin wax after all. Also where are you getting your temperature readings from. I am hoping the answer to the latter is live time OBD2 readings as that is where the car is getting its info from.
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Old 19th November 2019, 18:41   #36
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Hi all. Over recent months I have had new belts, thermostat, water pump, 2 speed fan and radiator. Temp is rising to 110 in stop start traffic before high speed fan brings it down. Operates at 92-97 in free flowing traffic. Getting cool air in passenger footwell and hot in drivers. Any idea what could be causing 110 operating temp and is this a problem?


Just another thought Dave your post states that you have changed water pump stat and rad. Was this because the car was overheating?
The car now has a two speed Fan what did it have before you changed it?
Very silly question, are you sure the coolant system is air lock free?


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Old 20th November 2019, 08:38   #37
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Could somebody provide me with MGR instructions to fill and bleed the cooling system? Thanks.
Here it is Dave.

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Old 20th November 2019, 12:24   #38
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Thank you for the various responses. The readings are being taken from the OBD pressing 19 - 7. The water pump and belts were changed when I purchased the car in July. The radiator and thermostat were changed as both were leaking. The fan was changed as I lost low and medium speeds on the previous 3 speed fan. I have fitted a new radiator cap and the system is holding pressure but does need a little top up every week. The pressure dissipates when the car has cooled down and there is no visible white smoke from the exhaust apart from at start on a frosty morning. The oil is clear. I have heard the sound of gurgling water from behind the dash at start/idle so the next step is to ask a reputable local garage to bleed the system to see if there are any air locks. Unless someone has another idea? Thanks.
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Old 20th November 2019, 21:04   #39
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Your gurgle will be an air lock they can be very difficult to chase out the system. I still suspect the stat is either opening late or not fully opening. If the weather down South is even 10 degrees warmer than up here, just now, I would not expect the car to be getting that hot in traffic in the summer yes I would expect the car to be calling for its fan every five mins in the town. Have you access to a digital sight thermometer to check on temperatures.
It could be the sensor is off. If you want a lone of one PM me and I will stick one in the post all I ask is when you are finished you return it. If you do want to borrow I will get one of the grand kids to go into the bowels of the garage and look for my engine diagnostic pit lane box I think there may be some colour change temp strips still in there if they are there and are in the correct temp range I will stick them in and you can stick them to the engine which will give you the block temperatures. Better on your car than in a box hiding for twenty years.
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Old 25th November 2019, 21:04   #40
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Hi Simon. You mention the SD1. I had the 2.6 and the 3.5. Sometimes I had a problem when it was very warm, that was before global warming, the temp gauge on the 3.5 would suddenly be showing that it was very hot. I found that this was a fault with a resistor that was under the top of the dashboard. It was evidently a well known fault on that particular model. I don’t know if the 75/ZT has the same type of system in operation, but just thought I would post this up.
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