I have an 87 4dr 740 Saloon which is too cold inside even thought the engine comes up to temperature perfectly

I have checked for coolant loss which is OK - so I am ruling OK the heater matrix core. The engine thermostat has been replaced. All engine coolant hoses are warm. The engine side of firewall heater hoses are both hot, and the hoses inside the cabin are hot - so I assume that the water valve in the drivers side footwell is OK (although there is a very very slight seepage of coolant as you move the valve - I assume it is the original part).

When moving the temperature control from cool to warm, the temperature changes from cold to luke warm (but not hot!). Checked the operature of the cable to the water valve (drivers footwell) OK - Does the cable move anything else that I cannot see? (I have not taken the full centre console out yet) as it seems to bend around over the centre console to the passenger side, then back to the drivers side. Is there a flap somewhere to control the mixture of outside air to air passed through the core? is this operated by the same cable?

Would any members recommend any service manuals for the brick (I have the Haynes manual - but it does not have much detail on the heater for example).
Any Ideas on how to get a Volvo dealer workshop manual??


Many Thanks and Happy New Year

Stuart

'90 760GLE V6 131k '87 740GL 2.3 60k