96 jeep cherokee 4.0 heater hoses diagram

should connect to the top

Get jeep up to operating temp
Turn on heater to max heat
Hood feel 2 heater core hoses goint into upper passenger side of engine compartment firewall.
They should feel too hot to hold
If it's not hot, could be 6 things
1. heater control valve is bad
2. Vacuum to heater control valve is bad
3. clogged heater core.
4. Bad thermostat
5. Bad waterpump
6. Needs more coolant (check when system is cold)

Do these things:

1. Disconnect vacuum line from control valve and feel under valve to manually move valve to open position. This should let hot water flow through core. If you now have heat inside, replace the heater control valve. Or you can disconnect the plunger on the heater control that is hooked on to the silver bar on the bottom of it. With it disconnected you can manually move it to the open position. It will always remain on.

2. When system is cold, disconnect both heater hoses going to heater core. hook up a water hose to one side of heater core and flush out any gunk. When you get done, the water should run clear. If you see lots of gunk come out, that was probably the problem. Replacement is like $20-30

3. When system is hot and engine running, squeeze the upper radiator hose (using gloves) when you release it you should feel a surge of water. Proves your water pump is working. If no surge, check thermostat. If thermostat checks good, look at the weep holes at the bottom of the water pump for traces of antifreeze. If you see a trace or stream of coolant, indicates bad pump.

4. As far as testing the thermostat, watch as your engine heats up on the gauge. when it gets to a certain point you will see the temperature rise, then lower, then rise again. This means your thermostat opened properly, cooling the system temporarily, then heated it back up. Replacement is around $5

Try these and see how it goes.

Try checking the heater control valve. Follow the heater hose from the engine, and as you get closer to the firewall, you should run into it. It is in line with the hose, and should have a vacuum hose connected to it. Apply vacuum to the valve and it should move. If not, then replace the valve. If there is no vacuum when engine running and heater turned on, then check the hose for leaks or the vacuum source.

have you checked the heater switch that is located under the hood, and is secured to the heater hose's. This switch will have two hoses connected on one side and two hose's connected on the other side, and is mounted on the side of the valve cover. There is a vacuum line connected at the top that controls the valve open and close function, allowing hot coolant to enter the heater core and provide heat to the interior. This is just one option I thought I would mention.

hi there.
check this link out might show you.
Where is the heater water control valve on 94 Grand Cherokee Limited...

The valve would be connected in line in the heater hose going to the firewall often it will have a lever attached to it with a cable, can also be vacuum operated, look for a vacuum hose, if it has one. Most likely the heater core is plugged.

check the water control valve in the heater hose inline to the heater core

Sounds like the heater control valve, not an uncommon failure item.

Dave

Under the hood on the pass. side firewall are two heater hose lines. Start the car and let it get at normal operating temp. One of the hoses is the "in" to the heater core, if you touch it it should be hot. The other hose is the "out" of the heater core, this hose should be warm and not really hot like the "in" hose. If the hose going in is hot and the other cold, then your heater core is clogged. There is a valve connected inline with one of the heater hoses, this is the heater control vavle.
If the valve does not open, you will not have any heat either.

Part you are referring to is your heater control valve. They generally develop small leaks where the actuator arm goes into the assembly. They are generally in the $30 dollar range and can easily be replaced.Don't forget to "top off colant level after repair!