Heater blows cold air only.

[MrBlueSky]

Hi, newbie here,

I have a 1990 S2 coupe that has no heat into the cabin. The heater control valve is in the fully open position and does not respond to changing the temp dial from fully cold to fully hot. Fan works on all 4 speeds, but no heat to footwells or screen. I don’t seem to have the ability to redirect the the flow either regardless of the position of the sliders. Can’t anyone help with where/what I should be looking at?

thanks Laurence.

 

[Waylander]

I would suggest it’s either the heater control unit connections on the rear or the unit itself

 

[marojojoem]

Laurence,
My 86 turbo had similar symptoms which were due to a failed ambient temp sensor under the plastic shroud close to the fan inlet under the bonnet.
Easy to get at and a cheap fix if that's the problem.
Mark

 

[marojojoem]

Oh and make sure the white plastic actuator arms on the control unit are all nicely intact and properly connected

 

[MrBlueSky]

Thanks guys,

Sorry for the tardy response, I've been travelling over the weekend and didn't have the means to respond. I will work through the suggestions and respond ASAP.

Thanks again,

 

[MrBlueSky]

Hi guys,

Just to let you know the outcome. I tried all the suggestions listed above but it turned out to be the heater control unit. Fortunately the car was still under warranty so I didn't have to pay for it!

Thanks for the help,