too darn hot

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Mon 21 Jan 2002 23:58
too darn hot - tim
just after a bit of quick help.

car: '97 ford fiesta

problem: with heater set to cool, the air the that comes from the vents is far warmer than it would normally be (very close to outside air temp), but full heat can still be obtained if needed. when set to the cold position the air is cooler when doing a steady 50, than when working the engine harder whilst "making progress" along a motorway.

result: I'm getting a bit peeved at having the sunroof open to keep the car cool when on the motorway! in case someone suggests using the air-con to lower the temperature, that is kinda pointless as it means the engine working harder, and so sends the temperature situation into a vicious circle, with the net result that the car gets only mildly colder.

i have read the relevent section in my haynes manual, but regrettably it isn't as detailed as would be liked. it has no wiring diagrams for the electronic coolant valve, and does not show any images of the heater unit.....

has anyone encountered a similar problem, or care to give some pointers?

appologies for the short and poorly written effort.

thanks in advance for any help people may offer.

tim.
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Tue 22 Jan 2002 13:09
Re: too darn hot - Andrew Smith
I'm confused. Is the car overheating ? Is this a problem with the interior ventilation system or the engines cooling system.
BTW the load on the engine from the air con is very small compared to the power needed to keep a car moving a 50mph. All you have to do is stick your hand out the sunroof at speed to feel the wind resistance your engine is constantly pushing against.
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Tue 22 Jan 2002 13:35
Re: too darn hot - tim
it's a problem with the heating system, in that it is impossible to completely turn off the supply of hot air to the car.

even with the fan turned off, the amount of air that is drawn through the vents as a result of the cars motion, is sufficient to make the interior too hot.
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Tue 22 Jan 2002 14:20
Ford TSB 123/1997 - Charles
There's a Ford Technical Service Bulletin for this problem. Your dealer should have a copy.
Basically its checking the functionality of the electrically operated heater matrix valve that cotrols the flow of water.

Hope this helps

Charles
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Tue 22 Jan 2002 15:12
Re: Ford TSB 123/1997 - tim
charles, thanks for that - it confirms what i did was correct.

I assumed that the valve was the culprit, so replaced it, but before i had chance to read your reply.

easy to change but an unnecessary £37 really.
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Tue 22 Jan 2002 18:23
Re: Ford TSB 123/1997 - Dave N
I think the TSB refers to the control panel also.
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