86' 944/No heat

[flmont]

I have a 86 944 that has no heat ...the blower works great ...its had a valve job over the last year...and I wonder if the vacume lines arent hooked up correctly ??? Thanks FM

[uvachief]

Check for vacuum leaks. Does your defrost work?

[longsail7]

Got the same problem. Not much of a problem in Phoenix, however I'm worried. Engine temp shows to be above the first hash mark. Car is running well. Defrost works but air is still cold, blower works fine. Any ideas?

[PorscheChef]

One of the most common reasons for no heat in the cabin is a broken plastic clip up behind the heater controls, to the right side of you gas pedal. They are very easy to replace and having 3 944s, I keep a few on hand. Porsche 924S/944/968 Heating & Ventilation - Page 1
Other than that you could be lookind at a bad heater control valve, which is connected to you vacuum lines, also rather inexpensive. But, I would check this little plastic clip first.

[Gawernator]

If the clip fails it should default to full heat, not no heat.

[PorscheChef]

Oh, very true. I withdraw my above statement. I would still check the heater control valve.

[flmont]

I dont have defrosters either...???? Thanks FM

[J1NX3D]

i have just got around to diagnosing my heater, also stuck on full, just this afternoon and yes its a broken clip. luckily for me i only have to pull my glovebox to get to it.

There's 3 per car, i could see only two though. the top arrow is the broken one.

[Gawernator]

Wait so that's where the second one is? lol I could only find one... and apparently there are three

[J1NX3D]

i found the 3rd, its part of the blower door for the windscreen/dash vents.
(will post a pic soon)

im still getting hot air though, where is this heater control valve and what does it look like?

Originally Posted by PorscheChef

Other than that you could be lookind at a bad heater control valve, which is connected to you vacuum lines, also rather inexpensive.

[Gawernator]

Ugh hope my other ones are okay -_- I replaced one

[J1NX3D]

heres the 3rd one. this is on my LHD parts car so if you pull your dash instruments you would see this. if you can change your air to blow on the windscreen to the vents its working fine.

[Gawernator]

Okay thank god lol

[J1NX3D]

Originally Posted by PorscheChef

Other than that you could be lookind at a bad heater control valve, which is connected to you vacuum lines, also rather inexpensive.

is #9 what im looking for? couldn't see anything obviously wrong with the vacuum lines or those valves.

[flmont]

Wow,..Great pic's guys Thanks FM

[J1NX3D]

it could also be this heater valve, item #27:

[89-944NA]

Originally Posted by mAd924

is #9 what im looking for? couldn't see anything obviously wrong with the vacuum lines or those valves.

Heater control valve is the un numbered object (with the single vacuum line running to it and the numbers 3 & 8 over it) in front of the brake booster IN THIS DIAGRAM.

It is located between the block and the firewall, over the speed and reference sensors. Make sure the vacuum line from the heater control valve is connected to the "tit" on the firewall where the large coolant lines go into the cabin....right side below the head/cam housing.

[89-944NA]

Originally Posted by Gawernator

Ugh hope my other ones are okay -_- I replaced one

Simple me, when we were working on your heating system, I forgot to tell you to check to ensure that the vacuum lines were connected to the 2 "tits" located on plate on the firewall where the coolant lines go into the passenger cabin.

In the second drawing the mad924 posted, the "plate" is the sort of triangular piece below the a/c evaporator. Below the coolant lines (a bit hard to see), there are 2 small metal "tits" these supply the vacuum to the HVAC system

[Gawernator]

Oooh. I have always wondered what that plate was and where it is. How do I access it?

[J1NX3D]

^ from your passenger footwell or the engine bay.

Originally Posted by 89-944NA

Heater control valve is the un numbered object (with the single vacuum line running to it and the numbers 3 & 8 over it) in front of the brake booster IN THIS DIAGRAM.

ok, that looks to be #27 in the other diagram. thanks!