I had a problem not getting vacuum to the hcv, so I decided to get a different climate controller. I'm swapping parts between the original and the replacement, hoping to get one functioning unit. The switch on the old one was partly bad, the max setting did not work. All the settings work on the new switch, and I repaired the vacuum wheel by taking a good clip out of the vacuum switch and putting small bolt/nut there to replace the clip I robbed. Anyway, the new issue is, no matter which controller I put in, or which switch, I'm getting constant defrost at every setting. Why? It never did this before even when the old crappy controller was in there. What has changed? And now the car won't start, sounds like the battery is low. That creeps me out a little, the battery is fairly new, and I didn't run the fan all that much while I was going through these tests tonight. I'll have to put a charger on it tomorrow.

 

Btw, one thing I noticed is that it made no difference at all whenI pulled the vacuum manifold off the wheel or vacuum switch, still full defrost, and there was no hiss when I pulled them off. No vacuum at the wheel or switch! That tells me there's a vacuum leak BEFORE the manifolds. Did something jiggle loose while I was working? If so, where, and how could I tell? But again, the engine was not running so I guess there might not have been vacuum there anyway, but I still shouldn't be getting full time defrost should I? Could it be the system depressurized when I took it apart, and now can't build up a vacuum to work right til the engine runs with everything together? I'll have to put a charge on the battery to find that out, but I suspect there may be more to it than only that.

 

Success! I think..... I wasn't just my dumbness of not having the engine running. I got it started and still had the same issue. Turns out the selector wheel needed a little more tightening, and the vacuum switch also, snugged it up, and also put electrical tape around the ports to make them seal better. Seems to be working. This is actually kind of a dumb thread--probably why there are no responses. After I started it I realized how dumb it was. My first time taking one of those things apart, didn't totally understand how it worked til I thought about it a little. When I read somewhere that the controller defaults to defrost when there's no vacuum it dawned on me what was happening. Rookie mistake.... Not the first time I've come off like an idiot, won't be the last--especially on here.

 

Lol I enjoyed your one sided conversation and you still figued it out so don't beat yourself up.

 

LOL

May I ask you what you meant with that?

thanks!

 

Glad you FINALLY got this resolved!!! I believe I asked you in your other thread if you had the engine running.......

 

It was my misunderstanding about how the hcv worked. I THOUGHT the vacuum was on when heat was selected, and that it diverted coolant to the htc when open. But looking at an old valve I had, and fixing all the vacuum troubles I had with my controller--I figured out its just the opposite. The vacuum is sent to the hcv when the temp lever is moved to cool, and THAT diverts some coolant FROM the htc. Under heater conditions, coolant flows from the tb downward through the valve and into the htc. When cool is selected, the vacuum kicks on, and that little valve in the hcv opens and some of the coolant flows straight across the valve from the tb, and is diverted down toward the oil cooler line where it joins the outflow pipe from the htc. Now it all makes sense, because AC is a luxury, but driving without heat could be dangerous. So still having heat if your vacuum isn't working right makes sense. This, like most work I've done over the past year, is my first experience with this component. So, it's a learning experience. But it was work well done because my vacuum selector wheel and controller switch were both shot, and I got them fixed now.

 

Lol, yeah, I put a charger on it for a couple hours and it fired right up.