too much heat in 98 Blazer
#11
02-02-2016, 05:32 PM
[That diagram was perfect enough- all of the hose colors were correct]
just went over all of the actuation actuators and levers. Everything is working properly. So, its most likely a leak/hole in the doors that close away the heat source from the rest of the ventilation... deep inside the AC module itself... and many many hours of labor/$$$
So, my neighbor brought up a "temp solution"- an inline flow regulating valve spliced into the water-in hose by the firewall, in the engine compartment. This way I am able to turn the hot water off completely, and turn it back on when I need heat/defog simply by popping the hood and opening the valve.
I have some concerns about this though: would the closed off hose cause back pressure? would the return hose get sucked flat? Both hoses come directly from the engine block to the firewall- and I am unsure what sort of flow/psi/pumping is going on to deliver the hot water to the heater core.
If it sounds like a good idea, or a horrible idea, please let me know either way- It will be a few hours to put the dashboard all back together again before I get started on any of that.
just went over all of the actuation actuators and levers. Everything is working properly. So, its most likely a leak/hole in the doors that close away the heat source from the rest of the ventilation... deep inside the AC module itself... and many many hours of labor/$$$
So, my neighbor brought up a "temp solution"- an inline flow regulating valve spliced into the water-in hose by the firewall, in the engine compartment. This way I am able to turn the hot water off completely, and turn it back on when I need heat/defog simply by popping the hood and opening the valve.
I have some concerns about this though: would the closed off hose cause back pressure? would the return hose get sucked flat? Both hoses come directly from the engine block to the firewall- and I am unsure what sort of flow/psi/pumping is going on to deliver the hot water to the heater core.
If it sounds like a good idea, or a horrible idea, please let me know either way- It will be a few hours to put the dashboard all back together again before I get started on any of that.
#12
02-02-2016, 06:37 PM
My guess is the slave door itself is stuck. The linkage and the actuator are on the outside, but the valve is not visible for inspection until you remove the entire HVAC case and disassemble it. The entire dash must be totally removed from the vehicle before you can remove the HVAC case. If you haven't done that job on a 2nd gen Blazer/Jimmy/Bravada/pickup, better plan on ~8 plus hours to remove and install. It would be a good idea to replace the heater core as long as you're in there 
As for installing a valve.... years ago the auto manufacturers used to control coolant flow through the core exactly like that. They found out the coolant can get stagnant, and cause other problems. Your vehicle should have Dexcool coolant, which is prone to "issues" if not maintained properly. Best to fix the problem the right way. In a pinch you can disconnect both hoses from the heater core and plug them together. Although not such a "hot" idea in the Winter You'd go from one extreme to the other!
As for installing a valve.... years ago the auto manufacturers used to control coolant flow through the core exactly like that. They found out the coolant can get stagnant, and cause other problems. Your vehicle should have Dexcool coolant, which is prone to "issues" if not maintained properly. Best to fix the problem the right way. In a pinch you can disconnect both hoses from the heater core and plug them together. Although not such a "hot" idea in the Winter
You'd go from one extreme to the other!
Thread
Thread Starter
Forum
Replies
Last Post