Ok so we went 4 wheeling with some friends yesterday and everything was going great, until my buddies GC broke a drivers side CV, so we towed him to base and shortly after we lost heat. The blower motor was pushing but it was cold air. Why would it all of a sudden stop blowing hot air?

 

I'm really tired so I'm just gonna start throwing some ideas out there. Don't do anything drastic until someone else chimes in.

Blower motor still running makes me think the heater core isn't getting any hot coolant. I'm not sure how renix hcv's work, but if they're anything like mine ('92) the valve is controlled by a vacuum hose. Check if the vac hose got knocked loose, Ten Bob's Bucks says that's the problem.

 

X2.... and i would check for leaking coolant underneath/coolant levels

 

open your hood and feel your heater hoses with your hands,with the engine warm.. the hoses run along the valve cover. the top one is the entry hose the bottom is the return, both should be close to same temp. if the bottom one is cold and the top is hot. that means that either you have a plugged heater core, or if your Cherokee has a heater valve then it is closed. if both hoses are cold you may be low on coolant and have an airlock ... hope this helps

 

Thanks for the replys fellas, we went driving around today and the heater started working, not very hot or very strong but some heat is better then none. Still a work in progress.