No Heat, HELP!!!!

twobitts · #1 10-24-2005, 06:54 AM

Got a 95 cherokee sport, not getting any heat from vents or defroster. Replaced radiator and thermostat about 2 months ago, also installed new heater hoses, and vacume controled flap. heater hoses get hot, can see the vacume controlled plunger activating, but hoses going from valve into firewall, cold as ice. Don't think heater core is clogged. Checked with lung pressure,(Not scientific, but works) blew in one hose, water came out of other. Please help.

vamc · #2 10-24-2005, 02:15 PM

heating core possably.

GregA · #3 10-25-2005, 02:36 AM

Quote:

Originally Posted by twobitts

Got a 95 cherokee sport, not getting any heat from vents or defroster. Replaced radiator and thermostat about 2 months ago, also installed new heater hoses, and vacume controled flap. heater hoses get hot, can see the vacume controlled plunger activating, but hoses going from valve into firewall, cold as ice. Don't think heater core is clogged. Checked with lung pressure,(Not scientific, but works) blew in one hose, water came out of other. Please help.

About all you have left is the coolant control valve and the hoses between that and the heater core.

When my Jeep (92) had the radiator replaced a couple of months ago, the coolant control valve "fell apart" when trying to get the hoses off. It had to be replaced.

Good Luck & Take Care,

Saudade · #4 10-25-2005, 12:47 PM

Exactly which hose is getting hot? If the hoses upstream are hot but the 2 leading to the heater core is not, then either the valve is not opening or the core is blocked.

Make sure the valve in installed correctly. Don't use your lungs, use a garden hose to flush the core out.

twobitts · #5 10-29-2005, 03:48 PM

hoses going from control valve into heater core are cold , hoses coming from thermostat houseing to control valve are hot. new control valve was installed at same time as radiator. connected hoses according to arrows on valve and diagram in haynes book, but did try other configurations, just to make sure. thanks for replys.

Dominic240 · #6 10-29-2005, 08:23 PM

temp control switch??

GregA · #7 10-30-2005, 01:55 AM

Quote:

Originally Posted by twobitts

hoses going from control valve into heater core are cold , hoses coming from thermostat houseing to control valve are hot. new control valve was installed at same time as radiator. connected hoses according to arrows on valve and diagram in haynes book, but did try other configurations, just to make sure. thanks for replys.

How about doing the following as a test:

Take a small piece of heater hose (a foot or two) and connect it in a loop from the "output" side to the "input" side of the control valve IN PLACE of the heater core.

Then run the engine until warm and switch on the heater. Feel the loop that you just installed and see if it is getting to be the same temperature as the hoses from the water pump & thermostat.

If both sides get hot, I would say it is a core problem. If the loop does not get hot, its a control valve problem (even if new).

Just a thought.

Take Care,

twobitts · #8 10-30-2005, 03:03 AM

good idea, didn't think of testing that way. will try. thanks

twobitts · #9 11-05-2005, 12:50 PM

Good news, ran the jumper lead of hose on the valve, turned out to be the core. Disconnected core hoses from valve, hooked a garden hose adapter to one hose and flushed with garden hose. Result, brown mud out from other hose. Flushed rest of system, and now have heat again. Thanks to all for the help.

GregA · #10 11-06-2005, 11:32 AM

Quote:

Originally Posted by twobitts

Good news, ran the jumper lead of hose on the valve, turned out to be the core. Disconnected core hoses from valve, hooked a garden hose adapter to one hose and flushed with garden hose. Result, brown mud out from other hose. Flushed rest of system, and now have heat again. Thanks to all for the help.

EXCELLENT! Now you can stay warm this winter.

Take Care,

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