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Work through the guide in order, and it should help you pinpoint the fault(s). Be sure to test the Dual Climate Control Valve (DCCV) as detailed in post #2.
pin 2 is power, pin 1 and 3 is ground if i hot wire it, it should close the valves, closing off the hot water, can any one see a problem with doing this
if it dosnt cut off the flow of hot water, it would prove the valve has failed, i think
You can also clamp off the lines to stop the flow of coolant to the heater core. This simulates the DCCV closing fully.
Or did you want to dig deeper and confirm the electrical side of the DCCV operation? I've got an idea for how to check DCCV amp draw at the fuse panel. This would check the electromagnets inside the DCCV and associated wiring. You won't have to access that nearly inaccessible connector on the DCCV for troubleshooting. I can elaborate if interested. It would be a 5 minute test with a digital multimeter.
" I've got an idea for how to check DCCV amp draw at the fuse panel. This would check the electromagnets inside the DCCV and associated wiring. You won't have to access that nearly inaccessible connector on the DCCV for troubleshooting. I can elaborate if interested. It would be a 5 minute test with a digital multimeter."
yes please
Your wish is my command. You are my guinea pig for this test method, as I have not had time to experiment on my car. Please be sure to post your results. If this test seems helpful, I will add it to my troubleshooting guide.
My intent is to measure the current flow through the two electromagnets inside the DCCV. When I bench tested a new DCCV for my '02, each side drew about 0.85 amps. I do not know if later models will be exactly the same, but they should be close. I also do not know what is considered a normal range, but I'd guess +/- 10% is fine. Also, you can compare the two sides and they should be pretty close.
The beauty of measuring current flow is this simulates real-world conditions in a loaded circuit. We'll be testing the component itself and the vehicle wiring all at once, too. If simply testing voltage and resistance in an unloaded circuit, it's very easy to get misleading results. I do not care to discuss how I know this... It's best to measure amperage whenever possible for the best results.
So far, so good? Have I lost you yet? This is what I do for a living, so forgive me if some of this seems like second nature. My boss says he suspects I was born with a meter in my hand... Here comes the part where I lose you. We are going to measure amperage by measuring the teensy voltage drop (perfectly normal) that occurs as current passes through a fuse *. Not a typo. We will determine amperage by measuring voltage. The good news is you don't have to understand it to get accurate results. Just hook up the meter as detailed, and you will be all set. If you want to overload your brain, you can read more details of the process here, or you can search for "voltage drop fuse test" or similar:
The circuit we will be testing passes through a red 10 amp minifuse, so scroll down to pages 5-6. Those are the only pages we will be using.
Pop your hood and open the front power distribution box. Make sure fuse F32 is red and labeled 10 amps. If not, install the correct size fuse.
2003 wiring diagrams here, if you want to follow along. See fuse F32 (direct battery power) in the front power distribution box on the right side of figure 01.2.
Note how this fuse feeds 3 circuits (boxes 70, 71, 72). You can follow them out to their respective figures. 70 is the common power source feeding both sides of the DCCV. This is the only circuit we want to measure. We need to disable the other two:
71 feeds the AC compressor clutch. Remove relay R8 (front power distribution box) to disable this circuit.
72 feeds the auxiliary coolant pump, found only on V8 models. Remove relay R7 (front distribution box) to disable this circuit. Relay R7 won't be present on V6 models. If you have a V8, disabling the aux coolant pump will remove any overheat protection, so keep an eye on the coolant temperature. It will also reduce coolant flow to the heater at low RPM, so don't let this drop in heater output trick you into thinking the problem is magically fixed.
Scared you off yet? The actual test is very simple, so don't be overwhelmed. Remember, you don't have to fully understand the technical details behind the process. Just connect the meter, push some buttons, and you'll have an answer right away.
Set your meter to millivolts. Your meter needs to be able to discern millivolts in the single digits. If not capable, there's a way around that I'll describe later. With the engine off, touch your meter leads to the two little recessed metal tabs in the head of the fuse. No current is flowing, so you should read 0 millivolts (0.000 volts) as there is no voltage difference between the two test points.
Start the engine, and toggle up the selected temperature until HI is displayed. When full heat is commanded, power to the DCCV is shut off and the valves spring load open for maximum coolant flow. Touch those two same points on fuse F32, and you should still see 0 millivolts as no current should be flowing.
Engine still running, toggle down the selected temperature until LO is displayed. This commands all heat off, so full power is applied to both sides of the DCCV to shut off coolant flow. With both electromagnets fully energized, the circuit should draw approximately 1.7 amps (0.85 each side x 2). The chart only goes up to 1.3 amps (13xx milliamps), but with a bit of extrapolation, your meter should show about 12.6 millivolts across the fuse.
To test each side individually, select the passenger side warmer while keeping the driver's side as low as possible. (I think you can only split a max 15F). Only the driver's side will be energized, so total current flow should drop to approx .85 amps. This will equate to 6.3 millivolts as measured across F32. Repeat the process for the other side.
If all tests pass, the electrical portion of the DCCV is fine, along with the vehicle wiring. If the air from the vents is still warmer than ambient with LO selected, the mechanical portion of the DCCV is sticking open and allowing hot coolant to reach the heater core.
If you meter won't read millivolts in the single digits, you have two options:
1) Get a meter that does. Most meters these days are capable.
2) Does your meter have a 10 amp range? If so, remove fuse F32 and connect the meter in place of the fuse to read amperage directly. Most meters have a dedicated internal fuse for this amperage range. This is very important, because when you remove F32, this removes all fuse protection for the circuit. One drawback to reading amperage directly like this is the logistics of connecting the meter leads to the fuse sockets. You can get special adapters that fit the fuse sockets:
* You may find yourself skeptical of the suggested test method, determining amperage flow by measuring a seemingly insignificant voltage drop across a fuse. I was skeptical, too. I did some bench testing, comparing these inferred results with direct readings from a variety of very sensitive (read: expensive) meters. I was impressed. This method was dead nuts on the money and highly repeatable.
The DCCV is cheap on eBay replace it, then take out the control panel easy sequence, then inspect the printed circuit that's in the base of same, chances are the DCCV has sent an overvoltage and blown one or two tracks. OK, have a competent electronic guy {computer] JUMP these tracks at the same time use an inline fuse 1.5 amp. Job done reinstall.
kr98664 ,i have read your post a few times, making sure i understand it, haven’t had time to look at it yet though.
i believe i have a serious gas leak in the AC system also
Sorry, it's not that easily followed however pm me if you like I can talk you through the process also have a look on youtube DCCV and climate module for S 2003 on keep looking you will find it and the instructions are easy to follow.
In regard to your Maybe gas leak take it to an auto elect and one that is recommended all systems are basically the same throughout cars.
cheers, Peter.
Also consider getting your module professionally repaired? They can even add circuit protection to help prevent that from happening again.
I have NOT used these guys but they do know all the problems and explain them well. Well worth reading it! Repair Climate Control Module
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did the tests, got 0.005 voltsTried to try each side separately, but still got the same reading
Are you saying you got this value individually for each side? I'm a little confused. With LO selected for both sides, you should measure double compared to when only one side is energized.
5 millivolts translates to 674 milliamps, or 0.674 amps. On my '02, I measured 850 milliamps for each side. Your numbers are not that far off from mine, and the later model DCCV may have a different amp draw.
Don't get too sidetracked with these tests. I'm was just hoping to verify the circuits feeding both sides are working properly. This also includes the ground supplied by the control module, including the internal traces prone to damage. Maybe this isn't a good test method, or it's too finicky to accurately interpret the results. Remember, even if the electrical portion of the valve is okay, it would appear the valve is not physically responding. I have not had time to play with my '02 for comparison, as I'm busy replacing the engine in my pickup.
knares I think you will far ahead to forget all this testing and just replace the DCCV. It's a well known failure and in my opinion all of them will fail with time. So just change it and move on unless you like science projects? I mean it's always fun to learn how it all works.
The longer you wait the more likely your going to blow up the CCM or the RCCM depending on your car. This is unnecessary IF you get the bad DCCV changed out quickly. I know about the DCCV and have always replaced them as soon as I knew they were bad. So I have never damaged a CCM/RCCM yet (Fingers crossed!).
Be aware that bad ones have been installed out of the box too. Also if it does NOT fix your problem that points to a damaged CCM/RCCM as mentioned above.
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I think you will far ahead to forget all this testing and just replace the DCCV.
+1 on that. I had suggested the science experiment in hopes of developing a simple test to make sure the wiring and module were good. Alas, the results were not the slam dunk for which I had hoped.
Heater
It's best to measure amperage whenever possible for the best results.
