20 Most Recent Air Conditioning and Heat for GMC Terrain Questions & Answers

check blend door and heat actuator

first thing to check is radiator full of anti freeze ? (water) you need water to run through the heator core.

if your radiator is not full of anti freeze (water) their is nothing to flow through heater core to make heater work.

You have a plugged heater core.

There are air sensors that open/close and mix the air...this is one of the GM product problems I have the same thing on my 2003 Sanoma..there are easy fix ones and unfortunately mine is the hard fix requiring the dash removal..the other is a door spring or plastic piece broken..can be seen just under the dash where the sir box is..easy fix..have it checked that is the common problem..Hope the best and good luck..

It's POSSIBLE, although it may or may not be true. Is this a continuous knocking noise with the AC running, or does it just knock a few times, then stop? If it's continuous, does it change in speed with the engine speed? At any rate, that vehicle SHOULD still be under warranty; the dealer should be taking care of all of that for no charge.

Is it when the air is on or off. If it is when the air is off you probably have a vent setting. In this case it lets air from the outside into the cab most if the time it's through the engine Bay Area usually there are vents around the bay but they still retain a lot if heat from the engine. If it is when the air is on a cool setting then you either have a low ac coolant level or your compressor is malfunctioning

There could be several reasons for this. The internal heat is generated from the engine coolant system and is controlled via an control mechanism which you activate by adjusting the internal heat settings. This control could be faulty, the air circulation fan inside your cab could be faulty or it could be a simple blown fuse. In many cases where a leaking heater system could cause engine overheating a lazy mechanic would bypass the heater function and restrict the engine coolant from circulating through the heater coils. My suggestion is to check all the above and you should have the problem sorted, good luck.

Your statement in it-selves solve the problem. Your vehicle cooling system and air-conditioner system work independently. Your vehicle cooling system is driven by the v-belt that turns the water-pump and circulates the coolant within the engine through the radiator and back into the engine and flow is controlled by a thermostat. Your vehicle air-conditioning system operates from a v-belt that drives an air-conditioning pump which circulates coolant through a sealed system and generates cold air completely independently from the engine cooling system. It seems that you need to repair the engine cooling system which has a fault and this fault could be a) combustion seeping into cooling system (blown gasket), b) cooling fan not operating (this fan engages at specific engine temperatures and suck cold air through the radiator in order to cool the engine coolant as it passes through radiator veins), c) faulty cooling thermostat (thermostats work mechanically and through temperature expands and opens the water circulatory channel / opening, and in cold weather restricts this opening in order for coolant to allow engine to reach operating temperature and then allows the coolant to circulate freely), d) engine combustion could be too hot due to fuel mixture discrepancies (too lean) thus overheating the internal combustion process which will overheat coolant, e) engine cooling system leak causing the system not to seal thus restricting the pressurised coolant circulatory system (the system needs to be pressurised for effective circulation as well as raising the boiling point of coolant (under pressure water would boil at 110 degrees Celcius instead of 90 degrees Celcius). Hope you find the problem soon as overheating is detremental to the engine and all integrate parts associated therewith.

Ac doesn't have anything to do with your ca overheating its a separate piece of equipment. If your overheating it's eithe your thermostat or a clogged radiator hose

sounds like a problem with either the dash unit, which is my guess electronic, or one of the servos that control the vent selection. there are two or three servos under your dash that control the airflow. when you select a position. the servo knows where to clock itself to select that vent. if the servo is dead, you get no operation from the vents. if the a/c unit has a malfunction, there could be a vent selection problem.

Most likely is the Thermostat that you would need to change .

The heat shouldn't have anything to do with your car turning off and on. If there is a knocking while the heat is on then you probably have a heater motor going out in you.

Could be! Perhaps there is an intermittent ground strap that is not making good contact. They are all over the place attached to the chassis and frame of the truck. Under the dash are the ones for the radio, and the radio antenna is the other ground where it connects to the body underneath. The Ac grounds follow the compressor lines.

once you take off the brake caliper you have to take off the big nut in the center of the rotor it might come off by hand or you might have to tap it off

i think i might know how to solve the issue... Check out this site he sells a module to bypass the security and that should help with it going off randomly. I know i used it in mine and i haven't had any issues since