Greetings,
Bear with me and my long-winded analysis. I am trying to be as thorough as possible, and who knows- perhaps some poor sap such as me stumbles upon this thread with similar issues. I know that this has been discussed through various forums, but I think I genuinely have stumbled upon a not-so-common issue.
The lack of interior heat and my subsequent attitude toward fixing it has been sub-par at best since owning this car. I purchased it knowing that the heat didn't work and the PO stated that it didn't work since he owned it, but it wasn't until I took early morning trips with the female unit in the passenger seat, that the heat even became an issue. Mind you, I live in Hawaii- so it's not as if I ever see anything below the mid 60's on a really shitty day in the middle of the "winter". All justifications aside, it's supposed to work and it doesn't.
Today I started the process of accessing my entire AC system connections, because that too, gave up the ghost slooooowly about two and a half years ago. Being in Hawaii...this is very nice to have. Right now, the AC system is very straight forward with replacing O-rings and what have you. However, the lack of interior heat has had me stumped until this afternoon when I actually began ruling issues out via tests since everything is accessible to reach the AC lines. Here is what I found, and I am hoping to get clarification from the forum members here.
Starting with the climate control and the ignition on, this powers 12v to the two-wire harness that plugs into the heater valve located near the driver side gas peddle. When the climate control is turned to the coldest setting, power is sent to the valve and that upper pipe of the two going to the heater core is activated shut/closed. When the climate control is turned somewhere around 20% hotter than its coldest setting, the 12v going to the heater valve is cut off, and the heater valve springs opened, allowing engine coolant to begin circulating through the heater core. I tested the climate control nob and the wiring harness and those are working properly. However, when the wiring harness is plugged into the heater valve, and the climate control knob turned up and down in temperature, the heater valve does nothing. So I suspect that the heater valve is burnt out. When activated with a 12v source, the heater valve must make a 'click' and is audible in some degree or another. I have another heater valve from a pulling yard, and I can confirm this by jumping it via 12v source.
The next thing I checked was for any leaks. Unfortunately, I have a very small leak somewhere that I have been unable to find. I am losing about four to five tablespoons every two weeks. I was sincerely hoping that I would find the issue when running the car and watching the interior heating pipes in action. While looking for leaks, I was able to physically touch the two inlet pipes coming into the interior of the cabin. Strange, the car is completely warmed up, but the heater pipes are completely cold. This is also confirmed when the radiator fan kicks on from the thermostat opening.
Next I had a look at the interior pipes coming through the firewall and it struck me like a truck- the upper hose has been cut, a black plastic T-fitting has been put in, and a small black hose is re-routing to some area just above the transmission into some small metal fitting. The pictures are better at explaining this than I may be. The lower hose is completely intact, with it diving along the firewall, bending toward the front of the car and connecting to some metal looking thing (the upper "bypass hose also connects to this metal looking thing!). After the metal looking thing, it bends up and around to connect to the rear-lower part of the head. The upper hose T's off, with the large side snaking down and around toward the front of the block. Please look at the photos to make sense of my nonsensical discoveries.
Likewise with the two interior heater pipes being cold when the car is warmed up, these two hoses on the engine side of the firewall are also cold. The upper and lower radiator hoses are both hot mind you. So what the frick gives? What is being bypassed at the firewall upper hose, and what the hell is that little medal thing sitting between the head hose/lower firewall hose connection? Also, I would like to mention that I did the "mess under the intake" a few years back. Some guidance would be outstanding!
Topic: No Heat, No Interior Heat, Strange Plumbing (Read 3360 times)