: 2000 Cadillac Catera... no heat... please help

12-06-10, 01:22 PM
The heat has been out in my Catera for quite some time. Neither side of the vehicle has heat. I have been doing quite a bit of reading about actuators and blend doors and thought I would check those first. Where exactly are the actuators located??? and the blend doors?

Its starting to get pretty cold out here and would be nice to have some heat.
Any information is much appreciated it. Thank you.

12-06-10, 01:44 PM
Also.... I don't know if this could be related. But the speed gauge and odometer don't work. I have done quite a bit of reading on that as well and it looks like I need a new ecm module. I don't think it is related because those things worked previously when the heat did not. But I figured I would mention it anyway. Thanks for your help.

12-06-10, 10:35 PM
HEAT: I just "fixed" my heat tonite. The blend actuators are located near the HVAC unit, lowest to the floor on driver and passenger sides. Your going to have to remove the plastic vents for foot warming under both sides of the dash. I simply removed the actuators and used zip-ties to hold the flap arms in the down position.

Drivers side, see the arm it attaches to... that needs to be brought toward the firewall.


Passenger side, same deal.


Another issue is the Heater Control Valve, located in the rear of the engine. This is a vacuum operated valve that goes bad after some time. The valve is bad and the flow of coolant doesn't open up to the heater core. That is what i would look at first.... then the actuators. Those two things went bad on me at the SAME TIME. I fixed the HCV, but the P/S vents were cold. Turns out both sides (actuators) were bad. I enjoyed a nice sauna on the way home from school after i fixed the arms.


I found that one of the Speedometer fuses kept blowing, so i went to autzone and grabbed a double fuse adapter. Place 2 fuses of same rating in the slots and insert the wires in where the fuse is on the block. Been 2.5 years and not once has it blown. IF that doesn't work then yes, you need a new EBTCM. Those signals are provided by the EBTCM. IF there not getting power, check your fuses under the drivers side dash. If the rest of the Instrument cluster is working but RPM and MPH, then EBTCM may need to be replaced.

12-07-10, 10:55 AM
thankyou for all of the good information. I actually just found out yesterday that the heater control valve has been leaking and just ordered a new one. I will replace that first and see if it fixes the problem. Otherwise I will dive into the actuator/blend doors.

When you had the issue with the speed gauge, did you also have the abs light on in the car? my speed gauge will work from time to time, and when it doesn't, neither will the mileage odometer and the abs/traction lights will come on in the vehicle.

Thanks again for your information.