S Type Jaguar heater blowing cold one side lukewarm other side

Hello, i’ve got a S Type Jaguar 2.7 diesel 05 reg, right hand drive (uk) the problem is on the passenger side heater is blowing Lukewarm on the drivers side blowing cold even if i set the temp up to maximum, could this be the heater control valve if so were is this located, if there is any help it would be great, thanks keith.

Certainly the heater control valve is the first suspect in the culprits lineup.
Next comes the electrical connectors that connect to it. I’ve put the bracelets on both those criminals. It took me a long time to trace and repair that little broken wire in the connector on the valve.
I don’t know which side it would be on a RHD diesel, but on my LHD 3.0 gasoline or petrol engine it is on the right hand side and low down, hard to get to unless you take other things off first.
You are looking for a thing with 5 hoses that looks like this.
PICT0082
What would a 5 legged cephalopod be, a quintopus?

That’s down right fugly

Hi the heater control valve, is certainly historically suspect, it bypasses water in its solenoid which results in drawing too much current (because the water can not be compressed) unfortunately this also sometimes results in the circuit board being blown in the heater control module
although difficult to reach, there are depending on which model vehicle a five pipe or 3 pipe heater valve easy to replace, you may wish clamping the hoses to reduce the need to bleed the coolant system afterwards