i have no heat or defroster.do you think it is a theromostat or the heater core.how can i check them and how to change them.thanks
Megunticook
10-13-2008, 07:55 PM
Is your engine temperature gauge behaving normally? If so, thermostat is probably fine.
Does the temperature lever on the heater control feel right? Is it connected to the valve in the engine compartment where you heater hose leads to the core? Have somebody work the lever back and forth and see if you can see the valve open and close.
If all that checks out, you may need to replace the heater core itself. Removal is pretty involved...not difficult, just takes a lot of disassembly to get to it.
Speed Dragon
10-13-2008, 08:06 PM
If the engine gets warm as normal, it's probably a broken heater valve cable.
moe7404
10-13-2008, 08:18 PM
moe in wichita ks
on the older mopars the heat lever was hooked to a cable in a housing that was clamped at both ends. if you moved the lever to fast the housing would come out of the clamp. so its best to move heater levers slowly. i guess old info is still useful
dolfans
10-13-2008, 09:24 PM
i just got the truck this past sat but today the gauge moved to the 2nd line after the c and the outside temp was about 50 this afternoon it was low 70's outside and the gauge moved to the 3rd line thanks
bookworm
10-14-2008, 08:01 AM
First things first. Check the coolant level. If it's low, it may not fill the heater core, yet still provide cooling for the engine, especially in cooler weather such as you have.
1972-D100
10-14-2008, 02:16 PM
Sorry but I have to ask the obvious question, is the heater by-passed? A lot of the time when a core goes out and leaks people will just by-pass it instead of fixing it.
If it is connected make sure you look close at the valve itself, I had one that you could move the cable back and forth all day long and it would mover the lever on the valve all day long, but the inside of the valve was stuck in the closed position the whole time. You have to look at the "stem" on the valve, it is what connects the lever to the guts inside of the valve, that is where my old broke loose.
impuresoul2k3
10-16-2008, 06:28 PM
Are both heaters hoses hot?
dolfans
10-16-2008, 11:09 PM
where is the heater core at and what does it look like.i know it is in the dash but what side.also where is the 2nd hose at.i am going to replace the top hose soon as i can.what size is it?i was also told i can bypass that valve in the middle of the hose,can i thanks
1972-D100
10-17-2008, 09:12 AM
The core is on the passenger side under the dash, there is a lot of disassembly you have to do to get to it. It looks like a miniature radiator. Do you have both heater hoses going from the motor to the firewall? if both lines are connect then the heater is not by-passed. Yes you can, by-pass the valve by just using a sold piece of hose and not installing the valve, but by doing so your heater core will always be hot and you may get the residual air flow coming across it into the cab, not a bad thing in the winter, but kinda sucks during the summer!
