944 S2 Heat on issue

[Outlaw944]

Well I report good news! @Tom

I manged to get some thermistors today and swapped out the mix chamber and cabin ones. I tested the two and the engine bay one and all read around 20,000ohm +/- 500ish. I tidied up the exposed wiring in the last pictures as well.

Once complete I decided to try one last time and put the control unit back on and instant succcess. Both cold and hot air was selectable with the push rod moving when doing so.

Can't thank you enough for the replies and the pdf document you took time to put together for issues like this. Really learnt some good knowledge of the cabin cooling system doing this and save a few £££s too.

The one thing I don't see is the heater control valve closing but assume its because that kicks in at higher temps when the system can't keep the cabin cool without do so. I only ran the car for a few minutes in the garage while testing not on the road.

Thanks again!

[Tom]

Well I report good news! @Tom

I manged to get some thermistors today and swapped out the mix chamber and cabin ones. I tested the two and the engine bay one and all read around 20,000ohm +/- 500ish. I tidied up the exposed wiring in the last pictures as well.

Once complete I decided to try one last time and put the control unit back on and instant succcess. Both cold and hot air was selectable with the push rod moving when doing so.

Can't thank you enough for the replies and the pdf document you took time to put together for issues like this. Really learnt some good knowledge of the cabin cooling system doing this and save a few £££s too.

The one thing I don't see is the heater control valve closing but assume its because that kicks in at higher temps when the system can't keep the cabin cool without do so. I only ran the car for a few minutes in the garage while testing not on the road.

Thanks again!

That's fantastic news! Congrats. I think all too often people check the valve and clip and then immediately start looking for a new control unit. The odds are usually in their favor, but your experience is a good reminder to check the $1 parts before buying the $700 parts. Did you use the thermistor parts I linked, or something else? Would be good intel to have part numbers that have been tested to work. I hope the experience has made you a Carpokean for life. Tell your friends.

[Outlaw944]

I did take a look but the shipping time was longer than I wanted. I'm impatient and had some time today to take a look. I found I had a store round the corner so I went and picked some up there.

The item was https://uk.rs-online.com/web/p/thermist ... cb2539cf49

Certainly a Carpokean now and hopefully I can offer some help in the future!

[Tom]

I did take a look but the shipping time was longer than I wanted. I'm impatient and had some time today to take a look. I found I had a store round the corner so I went and picked some up there.

The item was https://uk.rs-online.com/web/p/thermist ... cb2539cf49

Certainly a Carpokean now and hopefully I can offer some help in the future!

You had a store around the corner with that thermistor? Wow, lucky you. I live in the heart of Silicon Valley and I have to order online! Just checked the specs of the one you got and it's mighty close to the Vishay one I posted above. The b-value is a tad higher at 4080 but that's within the tolerance range I'm sure, and certainly WELL within the general vagueness of the dash dial numbers... If everything works, I think you're good to go with those thermistors. I trust you matched the specs while shopping and didn't just get super lucky!?!

[Outlaw944]

I guess the UK its more condensed so its easier for us with everything being closer! Yes, I did check against the specs to get the closet match. I think it worked out well. And we now have another option for everyone.

[Tom]

I guess the UK its more condensed so its easier for us with everything being closer! Yes, I did check against the specs to get the closet match. I think it worked out well. And we now have another option for everyone.

You did good!