Heat and Velocity Temperature Different Driver/Passenger Side.
#16
RL Community Team
Rennlist Member
Rennlist Member
The bottom view of the fresh air servo looks something like the picture below with an oblong slot where the arm passes through its mounting frame. When the arm is 90 degrees to the slot it is easy to pop the arm off the plunger rod that attaches it to the vent flap. Once the plunger is detached moving the arm parallel to the slot facilitates removing the servo as the arm passes through the slot. If the motor is still working in the servo the arm can be moved between these two positions by having the key in the ignition on or ignition off positions. If turning the key does not cause the arm to move then a more invasive process outlined in my earlier posting above's URL attachment is what needs to be done.
Here is the excerpt from that posting's thread:
"Detach the actuator rod and electrical connector from the footwell servo, just to the left (driver's side) of the fresh air servo. Using a #20 Torx on a flexible drive shaft, remove the two screws that hold the footwell servo bracket in place. Slide out the footwell servo. Pop of the actuator rod from the fresh air servo and remove the three screws that mount the servo to its bracket. Slide out the servo. (Remember, the motor in my servo was not working, hence I could not rotate the arm, and therefore the need to remove the adjacent servo.) My servo is now on its way to Partisan for a rebuild."
Here is the excerpt from that posting's thread:
"Detach the actuator rod and electrical connector from the footwell servo, just to the left (driver's side) of the fresh air servo. Using a #20 Torx on a flexible drive shaft, remove the two screws that hold the footwell servo bracket in place. Slide out the footwell servo. Pop of the actuator rod from the fresh air servo and remove the three screws that mount the servo to its bracket. Slide out the servo. (Remember, the motor in my servo was not working, hence I could not rotate the arm, and therefore the need to remove the adjacent servo.) My servo is now on its way to Partisan for a rebuild."
#17
Burning Brakes
I just had this diagnosed on my car, same issue as you- heat at low speed but cold air at higher speeds. I had my mechanic run the diagnostic and in addition to the fresh air servo showing a fault the footwell servo was also kaput. He removed both and I sent them to Partisan in Germany to have them repaired. Total for two is $384 with shipping.
The danger with assuming it is just your fresh air servo at fault is you miss another faulty servo. For me it's worth it to take it to a mechanic to have it diagnosed. I personally don't have the time or inclination to run my own diagnostics with an OBD2 reader but plenty here do it successfully.
The danger with assuming it is just your fresh air servo at fault is you miss another faulty servo. For me it's worth it to take it to a mechanic to have it diagnosed. I personally don't have the time or inclination to run my own diagnostics with an OBD2 reader but plenty here do it successfully.
#18
Rennlist Member
These cars have a hard time staying warm at speed in very cold weather as well. I have driven mine when it's zero or below and the motor barely heats up- so the heater doesn't work great either. I bypassed the rear spoiler so I can move it up and down with the switch, but it won't go up automatically. When the spoiler is down and I am running down the highway fast, the car will heat up much better than when the spoiler is up and the cabin will heat up. Minnesota will test the limits of the heater and the AC!
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M. Schneider (06-09-2021)
#19
Rennlist Member
Thread Starter
[QUOTE=PRSWILL;15489601]These cars have a hard time staying warm at speed in very cold weather as well. I have driven mine when it's zero or below and the motor barely heats up- so the heater doesn't work great either. I bypassed the rear spoiler so I can move it up and down with the switch, but it won't go up automatically. When the spoiler is down and I am running down the highway fast, the car will heat up much better than when the spoiler is up and the cabin will heat up. Minnesota will test the limits of the heater and the AC![/QUOTE
I am the original owner of my car and my lack of heat at highway speeds happened suddenly last week. It is not due to the ambient temperature.
I understand, however, what you are expressing regarding Minnesota's temperature extremes. Thank you.
I am the original owner of my car and my lack of heat at highway speeds happened suddenly last week. It is not due to the ambient temperature.
I understand, however, what you are expressing regarding Minnesota's temperature extremes. Thank you.
The following users liked this post:
M. Schneider (06-09-2021)
#20
Rennlist Member
PRSWILL, I do not agree at all.
I have used my 993 for many Norwegian winters, at temps down to -25 degrees C. No problems at all, at low or high speeds.
You should get your spoiler control unit checked/repaired. They sometimes fail.
Cheers,
Tore
I have used my 993 for many Norwegian winters, at temps down to -25 degrees C. No problems at all, at low or high speeds.
You should get your spoiler control unit checked/repaired. They sometimes fail.
Cheers,
Tore
#22
Rennlist Member
Thread Starter
No Heat at Highway Speeds '95 993 C4 Cabriolet
Does anyone have a drawing of the fresh air servo motor so that I can determine whether or not I am comfortable rebuilding my fresh air servo motor??
Thank you.
Thank you.
#23
Have you tried putting the top down?
(Sorry, couldn't resist. :-))
(Sorry, couldn't resist. :-))
The following users liked this post:
M. Schneider (06-09-2021)
#24
Rennlist Member
Am I confused? on my '95 993 there is a servo that controls a downstream vacuum motor. Is that the recirc flap? It's a set of louvers in the center of the cab side of the heater box - goes from the cabin to the backside of the evaporator... I had problems getting cool a air this summer so I zip tied that one open. I am wondering if that's a different servo than discussed here?
#25
Rennlist Member
Thread Starter
The following users liked this post:
M. Schneider (06-09-2021)
#26
Rennlist Member
Thread Starter
Am I confused? on my '95 993 there is a servo that controls a downstream vacuum motor. Is that the recirc flap? It's a set of louvers in the center of the cab side of the heater box - goes from the cabin to the backside of the evaporator... I had problems getting cool a air this summer so I zip tied that one open. I am wondering if that's a different servo than discussed here?
#27
Rennlist Member
The vacuum operated resirculation flap is controlled by a electric solenoid valve. The flap is supposed to open when you need fast cooling of the cabin by resirculating the air through the evaporator. This is all controlled by the Climate Control Unit.
f you are having problems getting cold air I would advise to test all fans and HVAC servo motors, see my DIY page here for details.
Cheers,
Tore
f you are having problems getting cold air I would advise to test all fans and HVAC servo motors, see my DIY page here for details.
Cheers,
Tore
#28
Rennlist Member
Thread Starter
Tore,
Do you sell the rebuild kits for the fresh air servo motors or only replacement motors?
If you do sell the rebuild kits is it possible to send me the instructions to determine what is involved to rebuild my car's fresh air servo motor?
Thank you for your help.
Do you sell the rebuild kits for the fresh air servo motors or only replacement motors?
If you do sell the rebuild kits is it possible to send me the instructions to determine what is involved to rebuild my car's fresh air servo motor?
Thank you for your help.
#29
Rennlist Member
I buy this from PARTisan Autoteile, they sell kits.
Changing the servo internals is done i 5 minutes.
Cheers,
Tore
Changing the servo internals is done i 5 minutes.
Cheers,
Tore
#30
Rennlist Member
Thread Starter
I removed my fresh air servo from my car tonight. When I removed my servo from the rod, I damaged the plastic retainer that attaches the servo from the rod. Is the plastic retainer normally damaged when removing the servo from the rod or did I create another headache?
Thank you.
Thank you.