[Alfisto Steve]

AR164-80 Checking 164 temp control stepper motor

Moving this info from this post: http://www.alfabb.com/bb/forums/164...ming-belt-water-pump-change-2.html#post474770

Now, new issue (sort of). I still have minimal heat in the ****pit. The steppers make no noise and everything seems to operate properly (shifting from floor to central to defrost, etc.). However, very little actual heat comes through. Any ideas on something simple to try? After spending around $2k plus the new tires ($400 for a set of snows) and exhaust ($300 for the 2 piece ANSA set) on my "new" car, I'd like to hold up on further expenses for a little while.

MarkZ

Stepper motors

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First off there are two stepper motors. Front one is the one doing the control of air flow out of dash and that is one the front one you have working for certain since you can change air flow from dash to floor to defrost.

No you need to verify whether stepper for temp is working and if so is cable from it hooked to temp door lever in blower motor housing located below base of windshield and passenger side wiper arm pivot point.

Open hood, remove plastic cover over a/c components behind false firewall and with a flashlight locate cable and lever deep down in black hole between blower motor housing and evaporator box. Now with key on and somebody at temp control button on a/c panel raise temp to full hot and see if cable pulls lever back towards ****pit. Go to full cold and lever should push lever full forward towards engine.

Report you findings.
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[Michael Smith]

On the 91L the stepper motor closest to the passenger compartment is the temperature control It adjusts the air blend flap as described. The air distribution stepper control motor is deeper in the dash and is the one that cannot practically be reached without pulling the dash.

The temperature control motor can be viewed by removing the inspection hatch from inside the glovebox opening (drop open the glovebox). This hatch is actually thee to allow replacement of the air blend temperature sensor. Why Alfa didn't also make provision for easy replacement of the steppers as, for example SAAB did, is anyone's guess.

 

[Alfisto Steve]

The temperature control motor can be viewed by removing the inspection hatch from inside the glovebox opening (drop open the glovebox). This hatch is actually thee to allow replacement of the air blend temperature sensor. Why Alfa didn't also make provision for easy replacement of the steppers as, for example SAAB did, is anyone's guess.

Only on 91-94 models but not on 95 with dual airbags and smaller glove box.

 

[Alfisto Steve]

Bob brought up a good point that maybe somebody has a heater core bypass valve or shut off valve installed in engine compartment where heater hose comes off rear of head. If no heat, heater core could be completely bypassed if heater core ruptured.

 

[MarkZ]

Waiting until I have a second person around to do the suggested test. However, I doubt that a bypass has been installed as there is some heat, just not very much. Between this amount of heat and the seat heaters, the car is pretty comfortable (with a coat on, of course).

Mark

 

[Alfisto Steve]

Waiting until I have a second person around to do the suggested test. However, I doubt that a bypass has been installed as there is some heat, just not very much. Between this amount of heat and the seat heaters, the car is pretty comfortable (with a coat on, of course).

Mark

You can locate the cable and lever, be sure they are hooked together and lever is not broken. If hooked up set temp to high and then you can look and see if lever is moved back towards ****pit for heat.

 

[BlackAlfa]

I always check the heater flaps lever by myself. Set the cabin temp to "Hi" (max), go take a look at the lever. Get back inside the car and set it to "Lo" (min), go take another look. I usually can see the lever in action - moving from one position to another!

What is the engine operating temperature? If the engine is running too cold (as in the case of a stuck open thermostat), you'll not feel much heat around this time of the year! Let the car idle until the radiator fan comes on. Note the temperature on the gauge (that may or may not be accurate) but now you know when the radiator fan kicks in. At this temperature, do you get more heat?

 

[MarkZ]

Brand new thermostat that did correct situation with very low temp readings. Now it comes up to about 187 or so (just to the left of the center on the gauge). I will check things out a bit later when it warms up to 20 degrees (at least no snow).

Mark

 

[Alfisto Steve]

Faulty thermostats

Well, it is a warm 33 here at oceanfront in VB this morning with just a dusting of snow. Weather going northern like today with a low of 19 tonight so going to leave the car doors unlocked as daughter's 164 has to be outside and it was raining last night before snow started. Don't want frozen door locks.

I, also changed stuck partially open thermostats in both my 164 and daughter's as neither one was warming up past about 160. Our 93L was only one that was warming up to correct 210 like our Jeep.

I plan to do some R&D this winter on machining an old thermostat housing to accept a thermostat capsule like most other cars do. I have had to change far to many thermostats even the Alfa neoprene poppets type to please me.

 

[Michael Smith]

Going below minus 20C here tonight but no rain! That's about -5F. One tip is to put lock de-icer and lock lube into your door and trunk locks before it freezes. This helps a lot because the isopropyl alcohol in most good lock de-icers will dissipate any dampness already inside the lock and the graphite in the lock lubricant will help prevent any water that does drive or leak in from sticking to the tumblers.

Finally, if you suspect frozen locks and the central locking won't unlock the doors then don't put the key in until you've first tried to get some de-icer into the lock and also heated the key either in your hand which will be good for most light icing problems or with a match or lighter for really stubborn and cold conditions. If you can't find lock de-icer (and it is the handy little squeeze bottle that you are actually paying for) try to find 100% isopropyl alcohol (don't use proprietary rubbing alcohol as that is cut with water) and a lock lubricant in the appropriate little squeeze container to get it into the locks. Empty out some of the lock lubricant and put in a slug of isopropyl and squeeze that into the locks.

Central locking was sent to humanity to allow us to deal with freezing rain.

Frozen locks are a common issue up here all winter every winter and leaving the car unlocked is not a permanent solution

 

[MarkZ]

Michael, we were talking about heater/stepper issues, not door locking. Luckily, I can leave my door locks unlocked at my house - very safe neighborhood. The deicer suggestion is a good one for anyone who cannot leave the car unlocked. Of course, getting it into the garage is even better, but that is another story again.

Anyway, on to the testing of the flap. I do see the servo moving when she changed the settings from low to high heat. It appears to let more of the air by a bit better when the heater is set to lowest setting, but when we move the setting up a few degrees, there is less warm air coming into the ****pit.

Thoughts?

Mark

 

[Alfisto Steve]

Michael, we were talking about heater/stepper issues, not door locking. Luckily, I can leave my door locks unlocked at my house - very safe neighborhood. The deicer suggestion is a good one for anyone who cannot leave the car unlocked. Of course, getting it into the garage is even better, but that is another story again.

Anyway, on to the testing of the flap. I do see the servo moving when she changed the settings from low to high heat. It appears to let more of the air by a bit better when the heater is set to lowest setting, but when we move the setting up a few degrees, there is less warm air coming into the ****pit.

Thoughts?

Mark

So do you get real heat when temp set to high? Is lever on blower motor housing pulled back into metal firewall closest to ****pit?

 

[MarkZ]

No, actually get more heated air when air temp is set to low. The piston arm moves something, but I don't really see a flap moving itself, but it could be my eyes. Is the flap a roundish rubbery item? It does not appear to move much (if so), but the shiny arm does move clearly out and in.

Mark

 

[Alfisto Steve]

No, actually get more heated air when air temp is set to low. The piston arm moves something, but I don't really see a flap moving itself, but it could be my eyes. Is the flap a roundish rubbery item? It does not appear to move much (if so), but the shiny arm does move clearly out and in.

Mark

Use a mag lite so you can focus on black lever attached to silver wire. If silver wire housing (coil spring looking housing over wire cable) moving then that is your problem as only inner wire attached to black lever should be moving black lever 3-4 inches.

 

[Michael Smith]

There were reports of the lever snapping off at the flap so it moved but the flap didn't.

You cannot see the flap, it is hard plastic and hidden within the heater box along with the separate air distribution drum.

Sorry about the off topic on lock de-icing but as we get this problem all the time every winter I thought a few Canuck tips might be in order.