Factory automatic climate control bypass/workaround.

[MinisterofDOOM]

Used V8 luxury cars can be a great way to get a lot of car (and performance) for your buck. Unfortunately, no matter how dependable they are, they tend to come with electronic luxury features that may not be on your must-have checklist. And when those items fail, you can be stuck spending a lot of money to repair things you don't really care much about.

Being a V8 elitist in today's market, I've learned to cope with this issue through ingenuity and junkyard parts. One such example: Ford's infamous Electronic Coolant Control Valve, which allows for dual-zone heater control. It's a solenoid-operated valvebody downstream of the thermostat that divides coolant flow between the two heater cores, and it is known for failing frequently. It's not a cheap part and--worse--the problem is often actually a harness connector failure, which gets even more expensive.

When mine failed in the summer (it fails open, which means HOT air constantly) my original fix was to open the solenoid housing and insert a small coil spring to force the solenoid open and attached coolant valve closed. This way I could use my A/C, but heat would not work. When winter came around, I realized I'd get sick of removing the valve and disassembling the solenoid every 6 months, so I needed a better solution.

My first choice was a '60s Chrysler-style manual heater valve, but of course nobody had those in stock. With the valve already removed, I didn't want to put the car back together with no solution in place, so I went to Home Depot and picked up one of these:



I got back home and pulled the inlet line to the controle valve. To add the valve in-line, I cut out a length from the middle of the hose, then I inserted the valve and secured the barb fittings with hose clamps. Unfortunately, due to the crowded arrangement of the hot-side coolant plumbing with the radiator and engine accessories, I couldn't leave the valve's handle on. However, it's still a pretty straightforward process to reach down with a pair of ChannelLocks and adjust the valve. If needed, the upper radiator hose that feeds this valve can easily be removed to provide better clearance.

Here's the end product:



Pretty simple solution to Ford's crummy electronics. Heater still works, AC still works--it just takes a manual adjustment to control which of the two you get. And because this line feeds RIGHT off the hot-side post-thermostat coolant flow, it tends to be a little TOO hot, so I can regulate the max temp by closing the valve partially and limiting the flow rate through the heater cores (something that wasn't possible with the binary solenoid-operated stock valves).

This valve has been in place for about 2 years now and has been working great!

[darylzero]

Nice Job

[WDRacing]

Excellent!

[Dattebayo]

Not trying to rain on your parade here, but it looks like you had enough clearance where you could have removed, rotated and reattached the handle to suit your space there...

[MinisterofDOOM]

That picture is with the upper radiator hose removed, so things are not resting where they do with everything reassembled. I thought the same thing at first (at most I thought I'd end up trimming the handle short and flipping it 180) but with everything put together it didn't fit and couldn't rotate more than maybe ~15 degrees, which is not enough to do what I need. The handle shaft is notched so you can't just pick your angle. Other valves might have a better handle setup, so it's worth keeping an eye out for that if you're going to do this yourself.

[Jesda]

Nice work!

Personally, I've never cared for dual zone climate controls. I feel like the passenger should throw on a blanket (I keep one in the car) and STFU. Plus, there's scorching hot heated seats to make up for my cool temperature setting. When I get into a strange car at the auction, I immediately look for the button to disable the passenger temperature setting.