94 850 Turbo heat blows cold always

Newman3son · Post by **Newman3son** » 15 Jan 2011, 19:11

1994 volvo 850 turbo sedan with ECC system.
Blower works fine thru all ranges in manual mode, from low, to full blast. in Automatic setting, as I turn the dials to higher temp, the blower increases in speed. the problem is the air coming out of the vents is cool, about 15 minutes into running, it is barely warm. It was 27 degrees the other day, and it never got warm inside the car on my 40 minute trip to work.

Thermostat is working fine. Engine temp gauge shows cold, then after about 3 minutes, moves to the 3:00 position and thermostat opens.

Pipes to heater core on both sides of the engine wall are too hot to hold for more than 2 seconds.
I have flushed the radiator system, heater core is getting very hot, I have removed the glove box and lower panel on passenger side to inspect things. the heater core plastic housing is warm to the touch on all sides, and the inlet pipes at the bottom are too hot to touch very long.

The recirculator actuator arm works fine, and switches from outside air to inside with no problem. Seems as though the airflow is just not going across the heater coil to heat the air.

The directional settings work fine, and control the air ouput according to the dial setting.....feet, face, both, auto, etc.

The ECC flashes when the engine is turned on. I have pulled the codes.

414 and 417 - driver/passenger side temp sensor fan seized. I don't see how this would keep the air from blowing across the heater coil.

I have read many posts on this forum, but can't find anything about the damper/divertor itself.
How do I find/test the dampers that control/divert the air across the heater coil?
Can I override the ECC, and make the damper divert the air across the heater coil?

Any info would be helpful.

Post by **phat78ta** » 15 Jan 2011, 21:27

Wow.
Imagine two people, with the same year car and the same problem, need the same thing on the same day. LOL!!!
I am having the exact same problem. I changed out the thermostat, and I know there are no clogs in the system
(pipes are hot and all) and I cant figure out the issue either.
I pulled 3 codes, 135(no signal from engine coolant temp sensor) 325( recirc damper motor active too long), and the same 414 code as you. The 414 code doesn't affect the heat output of the system unless the fan is set to "auto". Did you pull any other codes besides the 414? I'm eager for a solution too, as it's getting pretty chilly round here. I at least get some heat when the car is sitting at a light, and almost normal heat when idling in the driveway.

Post by **Ozark Lee** » 16 Jan 2011, 05:05

To both of you, Is the problem on both sides or just on one side (driver's or passenger's)?

...Lee

billy · Post by **billy** » 16 Jan 2011, 05:53

I am joining this club, my 94 850 turbo does exactly as you have thoroughly described. The only thing that saves my keester from freezing , is I live here in Fl., but we have had some cold nights this year and I have dreaded going out. Mine blows cold from both sides. I need help on this one to.

Post by **Ozark Lee** » 16 Jan 2011, 07:09

Welcome to MVS Newman3son,

You have done a terrific job of providing information. You next step is to inspect the damper flap motor(s) and the damper flaps themselves. The damper flaps are controlled by the lower motors on either side of the main climate unit and they are held in place with a couple of torx screws. The motors have a square shaft on the end that drives the damper flap up or down (opened or closed). The motors can fail but that usually sets a code in the ECC.

The biggest problem is usually the shaft itself, the shaft can split and the motor can no longer drive the damper flap. If the pieces are all still there the shaft can normally be repaired by gluing it and wrapping the outside with small gauge (22 to 24 gauge), uninsulated, solid copper wire, much like the joint on a fishing rod is reinforced.

Billy,

Since you are cold on both sides you need to check the heater core itself. The heater core is a high failure rate item with these cars and in places like Florida it is not uncommon for the previous owner to have discovered the leak and just bypassed the heater core.

These thing may help phat78a as well but things can get narrowed down more when I hear if that problem is on one side or both sides.

...Lee

billy · Post by **billy** » 16 Jan 2011, 07:22

Thanks , but I've checked already the heater core, and have even pressured up system (previously tracked & fixed a small coolant leak). It has not been by-passed either. What's the odds both damper doors are not operating properly?

Post by **phat78ta** » 16 Jan 2011, 09:21

I have the code for the recirc damper motor, but it switches from outside air to recirc fine. When driving, I just get lukewarm air. When the car sits, I get hotter air the longer it sits. I will look at the dampers and motors. Seems to me that whatever keeps cold air from coming in the car is not doing its job. My heater core is not blocked, and gets hot as it should.

Newman3son · Post by **Newman3son** » 16 Jan 2011, 14:23

In my case, both sides are blowing cold.....the passenger side, slightly cooler than the driver side. As I said, over time it warms slightly, but only slightly. Is there a diagram to show exactly where these damper motor and flaps are located?

to phat78ta, I had multiple codes when I first checked them. but since they had not been cleared in a long time, I cleared the codes, and then drove around for 10 minutes, and repulled the codes, ending up with just the 2...414 / 417

Post by **Ozark Lee** » 16 Jan 2011, 14:32

The damper flaps are located on both sides of the main climate unit, more or less just above the heater core. You need to remove the lower dash panels and the stiffener boards behind the carpet to get to them.

As with anything under the dash contortionism is involved. I have pictures of the mode damper but not the heat dampers so I can't really give you anything better than a description.

Once you find them you will know it.

...Lee

Newman3son · Post by **Newman3son** » 16 Jan 2011, 15:31

looks like I need to remove a large black barrier (knee bolster) just under the glove box that is in the way.
Says SRS on it....is this the passenger airbag? Its not going to pop when I try to take it off is it?