Gen1 LS AC Blows Hot On Passenger Side Went Through Threads


LVC Member
Apr 7, 2020
Reaction score
AC blows hot on passenger side. Have done extensive work on this. On second DCCV. First was aftermarket, second may be bosch do not know. The vendor replaced the part. Get that there are problems with some aftermarkets. The 1st one did not have any residue in chambers. This is doing the same thing it did with last DCCV. No residue in system, flushed, very clean before.

After replacing, testing with DCCV connected, one side has full 12volts of battery voltage, the other is reading about 8.95 volts (is that enough to open or close it? That is on max cool. Am wondering if I may be looking at an electronics issue like temp sensors (ie switch 2 sides)? A DATC issue with the low ground voltage on one side (one time during inline testing I had no voltage, ran diagnostics on DATC voltage came back, very weird). I did a number of wiring tests. List them below. If anyone has any ideas on what diagnostics or direction to go with this please advise? Lots of time messing with it.

I have full heat with max setting on both sides, no issues with heat. Have excellent ac on drivers side, just checked freon level, must be 38 degrees. Have never had a full heat all the time concern, always heat on pass side with ac.

Is it possible to install an inline hose pincher clamp for the passenger side temporarily until I can work on this more? Would it hurt anything as the DCCV cuts coolant off to that side anyway?

-bn/gr no voltage, reset, then 11.85 with valve connected this is battery power

-have good pin out from datc to valve for 2 grounds

-no faults on datc ever

-ran open wiring tests on DCCV wires, no opens to body

-did continuity test from DATC connector to DCCV connector, passed, read 0 on meter

-did not see any odd wiring issues when
It sounds like you have some blockage in the lines somewhere, ar ed you sure it's not something to do with your AC system, the Dual Climate Control valve seems to be working if you have heat on both sides so maybe you'll have to diagnose something else, I mean it is possible that you DCCV is faulty, I've ran both Motorcraft and generic brands, Motorcraft is the way to go, is your Auxiliary coolant pump original?
it is a 2000 with a 3.9 engine. I have max heat both sides, doubt any blockages unless it is causing the high heat? did you read my post, this is my second dccv with exactly the same syptoms. i noted the low voltage on one side of the coil, likely coming from the datc. details above. the original dccv had no residue in the valves. I have very clean motorcraft coolant in the system. I did extensive electrical testing, noted above. did you see any of that? what about interior temp sensors at the plenum or a datc? the negative voltage at one coil is about 9 volts, testing inline on battery power, is this enough to actuate the coil on the one side? could this contribute to high heat on pass side?
it is llikely the original aux cooling pump, it did not present any signs of failure. what problems can a bad one cause?

Members online

No members online now.