You can likely flush out the heater core.  You need to unhook the heater
hoses at the engine side and run a hose through it.  The heater hoses go
to the firewall and the core is on the inside of the firewall.

The best is to back flush it in the opposite direction of the flow, but
if you just flush it in both directions until it runs clear and fast you
should be ok.

It can make a big difference in inside heat.  If it doesn't help then
there are some blend doors inside the heater that can go bad.  That is
an expensive fix because the whole dash has to come off to get at it.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos:  Non members can still view!
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It could be the heater core. The heater core is located behind the dash
usually, and it can be replaced although it is best to let a
professional do it.

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