Joined: Fri Oct 14 2005, 09:41AM
Location: Hill AFB, UT
Posts: 4
I have recently replaced my motor and now my Heater doesn't work. It has a fairly new heater valve ( the thing that the heater hose's go into before going through the fire wall. The weird thing is that the A/c comes on when I hit the heater button. Any Ideas?
On the 69 there is also a wire that goes to the blower motor in the engine compartment. Odds are 70 is the same. When we swapped in my 440 this wire came off and made my whole heat/AC system go screwy.
Huh. . . I have a 71 Fury 3 that the AC goes on with the heat too. I just acquired a new switch I am going to try. There is a controller on the heater box behind the right valve cover I need to investigate too.
The following is straight from the 70 Chrysler service manual: When the ambient temperature is above 25 degrees and the heat or defrost buttons are pressed, the air conditioner will go on for a period of 2 to 10 minutes.(end quote) There is a round gizmo with two vacuum lines called a time delay relay on the engine side of the HVAC housing near the center of the firewall. It's purpose in life is to ensure that there is not enough moisture in the air to cause the windshield to fog up. On these cars the A/C will run in any mode. This threw me for a loop when I first got mine. Once I realized what was going on I pulled the connector off the low pressure switch mounted on the dryer and no more A/C engagment. I don't use the A/C and have yet to recharge it. What you folks have been experiencing is normal operation. I thought that it was a bit nuts myself and just wrote it off as the engineers trying to avoid inadvertent fuel economy. Hope this helps and also prevents baldness from un-neccessary head scratching!
Excellent 70! I have been waiting to get a copy of the factory manual, I won one on EBay, not here yet. In my case, the A/C keep running, an hour afterwards. I just located another timer, so we'll see. Now I know what that does. They weren't in the trucks
Joined: Mon Oct 31 2005, 12:48PM
Location: Bakersfield, California
Posts: 1755
Make sure the vacuum hoses are properly connected. The point about tbe compressor comming on is true, but if the vac hose to the front cannister is not connected, you will not get heat. The hose comes from the same vac outlet for the power brakes. Also, make sure the vac line is connected to the heater control valve on the hoses going to your firewall.
If either of these are not connected you will stay cold!
However, haviong said that, not all cars had the vac controlled heater valves. If yours is cable operated, you may have another problem.
