heat barely works, used to have a/c. help needed.

[jhaas63]

Vehicle history: 1972 Dart with a 318. Used to be a /6 car with a/c. The a/c has been removed (not by me). The heat barely blows luke-warm air.

What would you do to fix this issue? Several things are running through my head, thermostat, heater core, etc.

 

[TylerW]

If it's like any other backyard AC removal, you mean everything from the firewall forward got yanked and trashed.

Factory AC cars use a water valve mounted on the passenger fender apron. The original ones get frozen in one position over time and then you get barely any heat or heat even when you don't want it.

Check that first. No luck there, check the stat. No change there, then possibly the heater core is plugged. You can back flush them with a garden hose and moderate pressure.

 

[daredevil]

Is there a door between the evaporator and the heater core? If so maybe its in the wrong position.

 

[RedFish]

I would have to agree the water valve and/or vacuum lines to it is where the problem will be found

 

[cudamark]

Any of the above will cause it......I'd start with the water temp and flow. You can test that by grabbing the heater hoses and see if they are all hot and feel the same temp with the heater valve open. If you have a cold or luke warm hose, you have bad flow for one reason or another.

 

[jhaas63]

Any of the above will cause it......I'd start with the water temp and flow. You can test that by grabbing the heater hoses and see if they are all hot and feel the same temp with the heater valve open. If you have a cold or luke warm hose, you have bad flow for one reason or another.

The hoses going into the heater core are very hot when the motor has warmed up.

Also, I was looking at this thread...

http://www.forabodiesonly.com/mopar/showthread.php?t=160625

I do not have a vacuum amplifier under my hood. Does that mean that I will not have heat as long as I do not have a vacuum amplifier?

This is all kind of interesting and lame at the same time.

 

[cudamark]

The hoses going into the heater core are very hot when the motor has warmed up.

Also, I was looking at this thread...

http://www.forabodiesonly.com/mopar/showthread.php?t=160625

I do not have a vacuum amplifier under my hood. Does that mean that I will not have heat as long as I do not have a vacuum amplifier?

This is all kind of interesting and lame at the same time.

If both heater hoses are very hot, before and after any valve or heater core, it's unlikely to be a water flow problem. Next, I would check all the under dash servos and the push button vacuum control. It may be that the correct door is not opening for the hot air to escape. The fan is working I presume? The vacuum amplifier under the hood is for smog control.....not heater.

 

[yellowdartdave]

The vacuum amplifier under the hood is for smog control.....not heater.

Incorrect.

It is a storage reservoir for engine vacuum that controls the heat and A/C system.

Keeps the vacuum operated doors in their desired location during low engine vacuum situations.ie full throttle,etc.

If it was a smog control device, why do only A/C A-Bodies have them?

 

[cudamark]

Incorrect.

It is a storage reservoir for engine vacuum that controls the heat and A/C system.

Keeps the vacuum operated doors in their desired location during low engine vacuum situations.ie full throttle,etc.

If it was a smog control device, why do only A/C A-Bodies have them?

I think you're confusing a vacuum reservoir with the vacuum amplifier. The reservoir is just a tank that holds vacuum....the amplifier is a control assy for the EGR and related emission controls. You just need a good vacuum source to run the A/C dash controls. Most of the earlier cars just used a vacuum line straight off the intake but they found that on a long uphill run, there was insufficient vacuum to keep the system working properly, so they added the reservoir.