jtessaro

Regarding my '87 944 N/A:

Alright so 2 days ago the heater stopped working, doesn't matter where I put the heater control **** the air coming out of the vents is cold as the outside air, and this time of year that is no good.

I've done the standard checks for cars I have owned in the past. I checked the coolant which was a little low, nothing perilous, and I fixed it then drove it a bit and still have the same problem. I have yet to see coolant on the windshield so I assume its not a bad heater core.

I'm posting because, honestly I have no idea how the system works in the 944's. As far as I know it could be a relay between the control **** and the system, a stuck baffle, or maybe coolant is not getting routed past the heating core. I really don't know how it works, so I am not doing a great job of troubleshooting.

Any help would be greatly appriciated.

thanks,

josh

FRporscheman

I would try bleeding the coolant system. It could be while the coolant was low, air got trapped in your heater core. I would also check the vacuum line that goes to your heater control valve and make sure it's still connected and not broken. The control valve is right above the clutch housing... so right between the firewall and the back of the intake manifold. I hope you have skinny hands! Good luck.

catbug12

If your heater control valve is opening you have coolant going to the heater core and the problem is in one of the flapper doors not opening or closeing. You can see the valve opening and closeing if you watch it while someone moves your control **** from cold to hot. Vacuum for the valve comes from a solenoid that is located to the left of the glove box attached to the heater housing, by the heater core.If you go to www.clarks-garage.com click on garage shop manual then click on the letter H it will take you to the heater part of the manual.

jtessaro

It seems that the valve controlling heater flow into the heater core is being sucked shut no matter the position of the control **** (its not stuck as it opens when the engine is off). So I'm thinking that the switch may be bad and just causing the solenoid to run at maximum at all times.

Hopefully I will get a chance to take it apart tomorrow.

jtessaro

So it turns out that the filter on the air intake for the solenoid that controls the heater control valve was clogged and/or busted. Once I pulled it off the heat worked.

Now the challenge is figuring out where to get a new one.