Where is it and how is it controlled iit seems my heater is blowing cold

 

Sounds harsh but just makes sense:

“Let’s play a game.

You pretend that you are the only one that knows what year/engine/model, etc that you are asking about.

We will all pretend you never asked a question until you provide at least the bare minimum of information about your vehicle”.

 

Thanks cruiser you spoke for a lot of us!

 

LOL. Yep. No sense even trying to respond without accurate info.

 

That and the heater control valve only has about a billion topics dedicated to it on this forum that a quick search would reveal. Of those, 99% end up with the consensus of "just get rid of it".

 

I think this might be another one of those "one sentence question, first post" cases where a check of the IP and email addresses along with possible blocked links at the spam filter might turn up a known spam source. I could be wrong but after watching these for awhile now I noticed 8 out of 10 never come back to engage any further.

 

I am sorry about the last post I have a 97 4 door sport 4 0 auto 4wd 66k
the problem i am having is that my heater for no reason at all quit working i looked under the hood did not find a control valve the fan works thank you

 

Hey... A real person on the other end! Thank you for sharing that. I'm pretty sure the 97 does not have a control valve. Now you will have to go through a process of elimination. Starting with whether the engine is running at 210 degrees or so and If one or both heater hoses feel hot at the firewall where they hook to the heater core.

 

When was the cooling system last serviced? Thermostat controls the temp of the coolant, water pump pumps the antifreeze around. Heater core removes heat into the cab. Blower motor blows air across the heater core for heat.

One of these is NOT working as it should.

Is the engine getting up to 195 Degrees?
Are the hoses going into the firewall/heater core Hot? Is only ONE hose hot? (Plugged core)
Is your blower turning on?

 

FWIW I removed the HCV. Replaced it with a pair of these.

https://www.autozone.com/fittings-an...tor/102833_0_0

 

I checked the hoses today and yes the heater hoses were luke warm earlier this summer I had the water pump changed out it was supposed to flushed and filled with the pump, hoses thermostat.new antifreeze, this truck sat for a long time before I got it so probably the core is plugged I'm going to close this thank you all

 

Good job and good plan.

For clarification, 97 and later had no heater control valve..

And for the record, I've eliminated the valves on about 10 XJs/MJs, all with AC, all in Arizona, and they all work great.