Sounds like it could be a possible bloked heater matrix try removeing connecting hoses a jet-wash the matrix out both through the inlet and outlet until water flows free. The motor for the temperature door in the plenum isn't working. As you increase the temperature control on the dash, it sends a signal to a motor which opens the door to the heater core. Yours is sealing off the heater and allowing AC or fresh air only.
The temperature of the coolant entering the heater core is controlled by the engine thermostat. The engine coolant thermostat is generally located at the engine end of the upper radiator hose.
It's a BLOCK heater, not a radiator heater. It goes in the engine block, most of the time it goes where a freeze out plug is. You have to remove freeze plug to install it.
how do i replace a heater core in a 2001 Chevrolet blazer
how to replace a heater core in a 1997 Chevy blazer
Thermostat stuck open or heater core clogged. I had a similar problem in feb.2005 with my 1998 S-10 Blazer and it was due to the Dex-cool had turned to sludge , and that caused lots of problems. The first thing to do is after the engine is warmed up, feel the heater hoses going into the heater . if they are hot then the problem is in the heater, probably just adjustment or fuse. If they are just warm to cool then the answer is in the engine, probably needs a thermostat. answer can also be the temperature control switch in dasboard of car
The engine's thermostat controls the engine coolant temperature. The temperature control inside for the heater controls the cabin heat.
The only access to the heater core on a 96 S10 blazer is by removing the entire dash asm. It is not accessible from the engine compartment. If you are not familiar with disabling the the air bag system, do not attempt this repair.
Standing in front of engine it will be on the left side in the back towards the heater box.
At one hour on it hits 90* At 5+ it maintains around 125*. But temperature of block will vary with ou side temps due to heat not being able to exachange.
Could be, Stuck open thermostat, Low on coolant, Plugged heater core, Temperature blend door actuator malfunction.
Drain coolant from radiator and engine block Remove passenger's side rear freeze plug and replace with block heater kit
Inside engine compartment passenger side at firewall
To normally install a block heater you must remove an expanstion/ freeze plug in tighten in the block heater. The 6 cylinder 4.2L engine unfortunately does not appear to have any such plugs. The V8 engine should have a screw in style block heater installed in the left front of the engine block just below the cylinder head.
were is the heater relay on1996 jimmy?
It is in the engine compartment, up by the fire wall, left of the engine, on the plastic that covers the AC climate control system.
The heater might not shut off in a 1998 Chevy S10 Blazer because the temperature controls are turned up to heat. The makers of this type of truck and most GMC vehicles allow for constant air to flow throughout the vehicle at all times. In the summer, just turn the temperature control lower.
The heater door control on a Blazer can be replaced by purchasing a new one. The heater vent will pop out with a little nudge from a flat tipped screw driver. Then insert the new heater vent door control.
If this is about a car: the heater in a car is basically another radiator, but this one sitting inside the car. When you turn the heater on you draw heat from the engine and into the car. If you aren't running the car hard enough the temperature in the engine will drop.
Check the duo-valve first, then the heater register
The heater core is inside the heater unit on the passenger side under the dashboard
rad hoses route coolant to the engine to maintain operating temperature (to keep engine from overheating). Heater hoses supply the heater core (inside most vehicles) with hot water, when heater/ac temperature control knob is turned toward hot, to heat the interior of the vehicle by opening and closing a water flow control valve allowing water to enter the heater core for heat. =;)
You have to completely remove the dash to get access to the heater core.
you must have low coolant or a bad heater core
with your hands
normally when the heater core becomes plugged you will have n eat and you will notice a definite spike in engine temperature.