Projects like this always seem to evolve as you drive the car more and find things that don't quite work the way you thought. Hussein,
@lookforjoe, can probably testify to this.
The heat and AC was working fine, but on my way back home from
Italian Day at Griot's, I happened to rest my hand on the console and I thought it felt pretty warm. At first I thought it was because the sun was out, but nothing else in the interior was that warm. The more I drove, it stayed quite warm but nothing else. I had the heat turned off, so it was not coming from the heater core, but when I got home, I reached into the tunnel by the gas pedal and found that the pipes to the heater valve were very hot.
The Hurricane system I used, comes with an electronic bypass valve for the heater. I never really thought about it much and just followed the directions on how it works and installed it per the manufacturer.
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These aftermarket systems are primarily designed for front engine vehicles and so apparently the valve would normally be located somewhere in the engine compartment. I decided to put mine close to the heater core as it fit nicely there. To put it in the engine bay would have required to cram one more thing in the already stuffed cooling system, plus the wiring harness as it comes, was too short to reach, so I would have had to splice in more length. What I never thought about is that when the valve is "closed", it actually allows coolant to circulate in the pipes to and from the engine. When you open the valve, then coolant is directed into the heater core. It does provide "instant" heat, but because the coolant is always circulating in the pipes, those get hot and one of them runs inside the tunnel, which heats it up and that heat is what I was feeling through the console.
I realized that I really needed just an on-off valve like the stock install, not a bypass style. Old Air, who makes the Hurricane, does not offer just an on-off from what I can find on their website. I called them and they said that the only sell the bypass style as so many of their systems are used on LS-1 swaps which require a bypass circuit. I looked at the one from Vintage Air that Hussein,
@lookforjoe, had shown in his
thread but wasn't 100% sure that the electronics are the same as my system. The picture of it on the Vintage website only shows it from one view so it is hard to see if it is the same servomotor box or not, but it looks very similar. I asked Old Air if a valve from a competitor might work and if they happen to buy their valves from some outside source. They said the one from Vintage would not work with their system. I assume that most of these aftermarket AC companies source their electronic valve motors from a common manufacturer, but elected to try and work with the valve I already had, plus I already had the plumbing laid out for my valve.
I decided to just get some bypass caps from my local O'Reilly's and capped off the valve outlet and heater outlet fittings, then connected the outlet pipe from the heater core to the return pipe in the car. Basically, I tried to turned it into an on-off valve.
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I was a little concerned it might not work as I had hoped, since when I had it out of the car, I tried blowing into the inlet pipe from the engine with the valve closed and I could feel a little air leaking from the outlet going to the heater core, but I figured I would give it a try. The hardest thing was getting positioned on my back under the steering column to reach all of the hose clamps so I could remove the valve. The valve is located right above where the metal heater pipes come up out of the tunnel next the gas pedal. Of course, I removed the driver's seat, but it was still quite a contortion to get into position on my back, try and see upside down what I was doing, then extricate myself at each step. Sucks to get old. Fortunately, when I did the original install, I had angled the worm screws on the clamps to face toward the opening above the gas pedal, so at least I could get a nut driver on them. Here are photos of how I had it originally plumbed and then my changes.
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As some of you may guess, that little bit of leaking air turned into cooling leaking into the heater core even with the valve off. So with the fan running, I was getting warm air. It wasn't hot, but I didn't want any warmth if I didn't need it, plus the console got warm again. Back to the drawing board.
I messaged Hussein and asked if he had ordered the valve kit from Vintage and he had just gotten it. He sent me a photo of the motor side of the valve where the connector plugs in and I immediately knew it was the same motor. If you look at the photo above, you can see an embosssed logo on the motor body but someone had ground off something to the right of the logo. Turns out it was the name of the company that made the valve. Newbase Auto Electronics. There was even a stamped data plate on it that had the company website,
www.newbasecn.com. It is a company in China that makes a lot of auto electronic parts. I looked at their website and found the electronic heater valve. Turns out it comes in several versions depending on how you want to control the valve. My valve from Old Air has five wires, the same as the one that Hussein had. I called Vintage Air and ordered just the 5 wire valve as I did not need the whole controller kit. Here are pictures of the Vintage valve on the left and the Old Air one on the right.
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The first thing I did was to unplug the control wires from my valve and plugged them into the Vintage valve. I knew my controls would operate the valve, the only thing I didn't know was if it would go from closed to open when I slid my lever to the heat position. Just my luck, it was opposite from what I needed.
When my heat lever is slid to the left, i.e. full hot, the valve would close. So that meant I need to reverse the wires on my slider or at the motor somehow. Unfortunately, there are five wires going into the servomotor and I had no way to know which was which. When I was making my custom controls with the sliding rheostats out of the Old Air control panel, I got one of them the wrong way, so I had to unsolder the wires and switch them. I described this earlier in this thread. Unfortunately, there was no way to get access to the back of the sliders without totally disassembling the dash to get the heater controls out.
I knew there was a three pin connector coming from the rheostat that plugged into the Hurricane wiring harness and I was just able to get to that by removing the radio and the gauge cluster. That allowed me to just get my fingers in there to disconnect the connector.
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The contacts in these connectors are held in by little finger springs that engage the side of the holes in the connectors. They are a pain to try and release, but my plan was to try and get the black and brown connectors out and switch them as they come from each side of the rheostat. These contacts actually had one finger spring on each side of the pins. I made a couple of release tools from paper clips that I ground down flat and then slid in on each side of the contact which released them. I then swapped the brown and black, then plugged the connector back together and tested it. Success! Now the valve operated the way the slider indicates.
Now all I had to do was drain the coolant (again!), take the seat out (again!), and crawl back in there to swap out the valve. Here is it installed and it works perfect! Great heat only when I want it and it is infinitely controllable as to the temperature.
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I like this valve so much, that my plan when I retrofit my '79 with a modified stock X1/9 evaporator unit is to use this valve instead of the unobtanium and hard to get to stock mechanical valve. I plan to get rid of the lever that pushes the cable to the valve and do the same thing I did with this install. Mount a sliding rheostat in the slot for the heater control and get rid of the cable and it's issues altogether as well as having a reliable electronic heater valve.