Originally Posted by GraphiteGhost

Had the first one replaced under warranty because the fan was running when not told to, and at speeds not selected when told to. Now the replaced one is acting up. The A/C cut out last thursday while heading to the dragon. The compressor light was lit on the head and the compressor was running. Left it turned off for a few and it returned to operation like nothing was wrong (cold solder joint? Where have we heard of this?). Went to the dragon and last monday I did a little system checking. What I found was the heater valves near the battery (on the return side) were pulsing. The pulses were felt just like a pulse. The tops of both valves were extremely hot even when the heater line was cool (not much heat being demanded as in dialed to cooler side both zones). My question is, are those two return valves proportional? Or are they just open/close. I also would like to disect one of the heads and see if I can find any cold solder joints like the RCM has been having. I got lots of time and a few tools with a desk mounted mag lense/light that should get me real close on any board I can access. This is a failure mode troubleshooting so I am looking for one that is not working right. I will not be able to 'plug it in' to mine, I just want to see if I find something that might explain why the head malfunctioned. I then (if I find anything) will take mine apart and see if it is duplicated (given I find something in the first one). So, is there a malfunctioning one out there? I need all its faults discribed as best you can provide, and I will try to associate it with anything I find. Yes, it is all a guess (unless I find something significant). When my original was replaced, they would not give me the defective one. Something about they needed it back (a failure analysys) was the reason they said they could not give it to me. So, anyone have one they would like to donate? If I fix it (long stretch here) I would return it if you want providing you pay shipping here and back to you. If I can't find anything significant, you of course would get it back hopefully only slightly more worn out then the way I got it unless you don't want it (we can work out the shipping beforehand with both sets of eyes wide open so to speak). Oh, I did look to see if anyone else had done something like this but could not find anything. Again, I would like to know about the heater valves design/operation in its normal condition and a control head that is not working right to see if I can find something indicitive of an easy fix (like the RCM repairs). Any thoughts, suggestions, explainations of the valves, and a head you can pretty much donate to help find some chance of a fix for these things?

Originally Posted by GraphiteGhost

180, I read the link, thanks for that it showed a detail I needed to know if it was proportional or on/off. I also found out why the duo-valve is hot when not calling for heat! Its failsafe open (heat mode), it requires current to close. Also, it does pulse based on a littany of inputs from all the temp sensors and the sensors in the A/C system, as well as the settings/demand from the driver/passenger.

Originally Posted by GraphiteGhost

On the 2008 Crossfire (mine) the valves 'pulse' based on the description on page 24-165 (Coolant Circulation Valve) of my 2008 manual. The last paragraph under (Operation) states " In normal operation the A/C Heater Control module switches the ground connection intermittently. The locking and closing times of the coolant circulation valve are subject to deviations between the actual temperature and set temperature ". Intermittently to me means on/off in pulses. I found 'pulses' directly somewhere else in the manual but if this post doesn't satisfy you I will reread until I find it. Maybe I will try to find the word 'pulse' or 'pulses' in the .pdf, or since it took me over two hours to find this reference, can you look for 'pulse(s)' in the .pdf?

Originally Posted by GraphiteGhost

C-mon guys n gals, no one has a head they replaced because of a 'this or that' thing wrong with it that they can donate to a possible worthy cause?

Originally Posted by GraphiteGhost

Well, I sure am not going to give up, just ask those who post-ingly beat me up on the descreening of the MAF thing. Old addage I have even when the odds are 0.000001 to 0.999999, I like to think I might be THE 1..... Maybe someone sometime will look at their part in a box somewhere and will say to themselves "This has got to go" or their other half will say "That has got to go" (if in a relationship that is). Anyway, just don't send me one that was run over or submerged/taken apart before if your going to send one. The little spark of curiosity I have since I was about 4 or 5 (supposition here) is still active. Just need a few added tools (got a large magnifying circular flourescent light and just recently, a magnifying head band) but will soon need something to stabilize a quirky left hand/arm shake. All offers for one gladly accepted! PM me, I'll not mention your nick/name just that I have one. Maybe we can get this thread up to the numbers the BEGi thread is with 'Where is the fixed head' comments (JUST KIDDING). Anyway, I'll never give up!