Vinsanity
Member
So my heater stays on regardless if I push the off button. I heard you can make a bypass using prestone.. idk but need this problem fixed. Does this have to do with a heater core?
Heater stays on
- Thread starter Vinsanity
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PurpleBeeper
Member
What car? I doesn't directly have to do with the heater core. The heat is shut off in Mopars by one of two methods that I'm aware of. Either there is a heater control valve, usually under the hood in one of the heater hoses, which closes off the flow of hot water to the heater core OR there's a "flapper door" near the passenger's feet which directs the air flow into the car, either through the heater core (heat) or around/past the heater core (no heat).
In most cars I've worked on, there is a cable (similar to a bicycle brake cable) which connects the switch on the dash to either the heater control valve (under the hood) or the "flapper door" by the passenger's feet. The cable will connect to a small metal arm (both types) which you can move by hand. Sometimes the heater control cables just pop off that small metal arm or the switch in the dash.
In most cars I've worked on, there is a cable (similar to a bicycle brake cable) which connects the switch on the dash to either the heater control valve (under the hood) or the "flapper door" by the passenger's feet. The cable will connect to a small metal arm (both types) which you can move by hand. Sometimes the heater control cables just pop off that small metal arm or the switch in the dash.
Vinsanity
Member
It for a 67 fury 3
"Does this have to do with a heater core?"
Only in the sense that the heat does come from the heater core... it's a small radiator inside the dash area.
"I heard you can make a bypass using prestone.."
Prestone is a brand name, but they did/do make cooling system adapters for flushing... which could be used, under an appropriate tree, to create a bypass. You would connect the 2 heater hoses together with the adapter, but you won't have heated air for heat or defrost anymore... a bigger issue in some parts of the country than others.
This is an easy task, but please make sure you capture the old coolant for proper disposal. Replace the old coolant with a proper 50/50 mix of ethylene glycol coolant for the best protection against corrosion of your cooling system. If you decide to mix it yourself, use distilled water. If you can't figure any of this out, let us know.
Please clarify - is the blower motor still running or is heat just coming out when driving?
If the blower still runs you have a switch issue.
If heat still comes out (but the fan is off) you have a problem with the heater box door as described above.
If the blower still runs you have a switch issue.
If heat still comes out (but the fan is off) you have a problem with the heater box door as described above.
Does this car have air conditioning too? I'll bet you do because you are saying "push the button"...
With an A/C equipped car, there is a vacuum operated switch that the push buttons attach to. That switch tends to break and/or the vacuum hoses running to it come apart. It's usually available on places like eBay, but usually not cheap.
You really need to download a Factory Service Manual for this car. This will help you a lot. MyMopar - Mopar Forums & Information - Service Manuals
This is the dash vacuum switch.... All pics grabbed from the 'web.
This one has broken nipples, but it shows how the push buttons attach.
Same switch, showing the vacuum lines and electrical hook up.
New switch.
With an A/C equipped car, there is a vacuum operated switch that the push buttons attach to. That switch tends to break and/or the vacuum hoses running to it come apart. It's usually available on places like eBay, but usually not cheap.
You really need to download a Factory Service Manual for this car. This will help you a lot. MyMopar - Mopar Forums & Information - Service Manuals
This is the dash vacuum switch.... All pics grabbed from the 'web.
This one has broken nipples, but it shows how the push buttons attach.
Same switch, showing the vacuum lines and electrical hook up.
New switch.
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The 7-digit stamped number usually is the correct Chrysler part number for the item pictured. What's on your control valve can be different, so verify that prior to purchase. Use THAT to determine which one to buy, not relying just on what the seller says it fits in a chart.
In the FSM, there's a specific section on "Heater" and one on "Air Conditioning". Two different systems in how they are configured and installed. The heater section on an a/c car would be diagnosed in the "Air Conditioning" section. Please note how the heater hoses are run from the engine, any "water control valves" which might be in the system, too. There are also arrows in the hose routing picture, to make sure the water runs the correct way.
As noted, is this a fan running issue or an issue of heat happening via air flow? On the flapper doors, there is a narrow rubber section which can deteriorate as it seals the duct when it's closed. OR, are there some firewall seals/plugs which are missing and letting engine heat migrate into the passenger compartment? Something tells me that somebody has addressed this issue, somewhere along the line, by not repairing it "to factory specs", possibly?
Might need to start the diasnosis from "square one", making sure the heater hoses are run correctly. Then that the fan switch is working correctly. Those are the easier things. Then you'll need to get into the rh front floorboard to check the operation of the and vacuum actuators as you work the control panel items, one at a time. To make sure that air flow changes appropriately between the ducts and outlets. Making sure the vacuum lines are intact and functioning. As I recall, these vacuum lines are not of the same rubber composition as what you'd buy at an auto supply store, although the auto supply store items CAN vary in quality by observation. Tell the clerk what you're going to use them for so you can get the correct/better/thicker hoses for that use, if needed. AND, of course, the hoses to the vacuum supply from the engine are very important, so check that too. All of these things will be taking place outside of the heater box/case. From there, some disassembly might be required, which is where having the FSM available is necessary.
Please advise . . .
CBODY67
In the FSM, there's a specific section on "Heater" and one on "Air Conditioning". Two different systems in how they are configured and installed. The heater section on an a/c car would be diagnosed in the "Air Conditioning" section. Please note how the heater hoses are run from the engine, any "water control valves" which might be in the system, too. There are also arrows in the hose routing picture, to make sure the water runs the correct way.
As noted, is this a fan running issue or an issue of heat happening via air flow? On the flapper doors, there is a narrow rubber section which can deteriorate as it seals the duct when it's closed. OR, are there some firewall seals/plugs which are missing and letting engine heat migrate into the passenger compartment? Something tells me that somebody has addressed this issue, somewhere along the line, by not repairing it "to factory specs", possibly?
Might need to start the diasnosis from "square one", making sure the heater hoses are run correctly. Then that the fan switch is working correctly. Those are the easier things. Then you'll need to get into the rh front floorboard to check the operation of the and vacuum actuators as you work the control panel items, one at a time. To make sure that air flow changes appropriately between the ducts and outlets. Making sure the vacuum lines are intact and functioning. As I recall, these vacuum lines are not of the same rubber composition as what you'd buy at an auto supply store, although the auto supply store items CAN vary in quality by observation. Tell the clerk what you're going to use them for so you can get the correct/better/thicker hoses for that use, if needed. AND, of course, the hoses to the vacuum supply from the engine are very important, so check that too. All of these things will be taking place outside of the heater box/case. From there, some disassembly might be required, which is where having the FSM available is necessary.
Please advise . . .
CBODY67
'66 Polara, A/C car, the vacuum lines aren't connected so I can't select where it comes out, dash, floor, windshield, but I can select the temperature I want by sliding the lever to where I want it. But I still have heat coming out the vents if I leave it on HOT. Same thing with cold air. Don't know if this sounds like what's happening with your car, but that's my situation, thought maybe it might she'd some light on your situation.
commando1
Old Man with a Hat
These AC slabs have a Rube Goldberg heat control valve. The cable is a 2 piece affair connected by a pivot arm. After years of wear, I rarely see these things working properly and results with the HEAT alway on regardless of where the slide lever is.
There. I helped.
There. I helped.
On the '66 Chrysler, the water valve, with the capillary tube, looks similar to the '55 Chevy factory water valve. '69-'73 valves are more rational in their vacuum or cable operation, it seems. The capillary tube is allegedly supposed to keep the temp the same as engine temp might vary some?
The '72-'73 cars also use a 2-piece cable, plus a switch to turn the compressor off with higher heat settings on the control panel . . . on the ones with the cable system. My '70 Monaco has the full vacuum water valve, but the '72 Newport has a cable system.
CBODY67
The '72-'73 cars also use a 2-piece cable, plus a switch to turn the compressor off with higher heat settings on the control panel . . . on the ones with the cable system. My '70 Monaco has the full vacuum water valve, but the '72 Newport has a cable system.
CBODY67
Gerald Morris
Senior Member
These AC slabs have a Rube Goldberg heat control valve. The cable is a 2 piece affair connected by a pivot arm. After years of wear, I rarely see these things working properly and results with the HEAT alway on regardless of where the slide lever is.
There. I helped.
I pulled my vac switch altogether and just rotate the shaft which was cranked by the large bellows the vac switch regulated. I can adjust the heater/defroster through every setting this way. Mind you, a '66 is a MUCH simpler machine than the Formals are, but my point is that one can contrive a handle or knob to crank that switch in the heater box instead of spend C-notes on the vac switch, pretty bit of Rube Goldbergery that it is.
By doing this, I also eliminated the need for the ONE vac connection to my intake manifold. All I need is the ported vac for the advance. Nice to have a clean setup like that.
live4theking
Old Man with a Hat
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As said above start at square one. Put the hood up and follow the heater hoses. This could be as simple as someone removing the valve. How about posting a couple of pictures for us, under hood where the heater hoses run and the dash controls for a start.
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