HVAC display gone

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AZQ45
Posts: 87
Joined: Sat Jul 27, 2002 10:12 am
Car: Q45, G35, My 3 sons, hockey, snowmobiling (when I can)

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"Climate control display winking on/off My display suddenly went out yesterday, but came back on the next time I drove the car. I went out again this morning, but when I turned the car on and off it came back on. The system still works (thank God), you just cannot see the display.

Thoughts?"

Now it is totally gone. It still works, but no display. If anyone sees or hears of a 91 HVAC controller available please let me know.

Thanks...


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greg_atlanta
Posts: 1110
Joined: Tue Jul 23, 2002 4:37 pm
Car: 2008 G35 Journey Sedan, silver/black (no sunroof), 1992 Q45 (in a past life)

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You might be able to live without it.... since it's an automatic system, all you have to do is select Auto or Econ. If it's summer, remember 65 degrees is the bottom, and if it's winter (or whatever you call it in AZ) 85 degrees is the top.

When in doubt, bottom out or top out (press the up/down 15-20 times), and then count up or count down as needed.

Figured that's what I'd do if mine ever konked out.

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firedane
Posts: 40
Joined: Mon Jul 29, 2002 7:44 am
Car: gearhead, restore old houses, computers

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A couple of ideas. 1) send to Jerry Tucker and he will repair it for $100.00 plus shipping. 2)Go find the post by deesolballs. He took his apart and found where it was bad. Resoldered as I recall and he was good to go. I would not trust a boneyard part, as this seems to be a common problem. Very likeley to get another bad unit.

firedane

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Q451990
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Car: 1990 Q45 - 118K, 2022 Toyota 4 Runner, 2004 Frontier M/T - 108K, 2012 Xterra (Mom's), 2023 Rogue (Inlaws)
Location: Columbia, SC
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I think that was all on the old UBB board... maybe they can find it and post as an article? I don't think it was dees that fixed his DIY, but I may be wrong...

Heath

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firedane
Posts: 40
Joined: Mon Jul 29, 2002 7:44 am
Car: gearhead, restore old houses, computers

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You were correct. Dees did not fix his controller. However, he did find the excerpt from the old site. Here is what Dees posted in the Infiniti General section written by Lon Allen:****************************************************Here is Lon's experience...

Decided to attempt to discover the notorious A/C readout failure this Saturday. Disassembled the A/C control box. Tried as many things as I could to no avail. Finally I remembered that one of the posters on this board was able to get the readout to work if he flexed one of the boards. Seeing that the board that has the readout mounted on it does not have that many components on it I decided to try and do some flexing on the main board (the one that plugs into the harness in the dash). Lo-and-behold, if I flexed the board in a certain way while it was attached to the dash harness the readout would start working. I narrowed it down to a one centimeter area on the board that I could put my finger on and push and the readout would come to life. Back at my soldering station I resoldered two different resistors and that was the fix. Hasn't stopped working since. Replaced all the lights and it works like new. Replaced the bulb in the power window cut-off switch as well (that was a task in itself). Had to take the switch apart (snaps together). The bulb in the switch is the same as the A/C backlight bulbs (radio shack $1.49 for a 2-pack). The bulb itself is mounted in a rubber holder that sits on top of two wide pins. The bulb leads are threaded through the holder in such a way that when it is pushed back on the pins the leads come in contact with the pins. One thing I noticed that might be the root of many of the A/C readout problems is that the capacitors on the main board are all leaking electrolytic acid just like the ones on the speaker amps. These caps are from the same manufacturer (nichecon) and are of the same family of caps based on the color of the cap wrapper (brown). When I ordered caps to attempt to replace the ones on my speaker amps the manufacturer representative sent me black caps as the replacement. Apparently the brown ones were prone to failure and this is evident on the A/C readout controller as well as the speaker amps. I cleaned all the dried/hardened electrolytic seepage off of the few caps that there are hoping that this might get the readout working (that was the first thing I tried). I did not have two of the caps in my current supply, so I wasn't going to go through the trouble of just changing one to attempt to fix it. The plan was to order the caps and try the fix at a later date. The test of flexing the board was a last minute test before buttoning it up.

If the caps are the real problem and the solder joints on the resistors are only secondary I will most likely have to revisit this issue at a later date. At least now if it is the caps I have a game plan to fix that when the time comes. I can't see the solder joint thing being a wide spread issue that would effect so many of these readouts, but if there were an issue in the manufacturing process (where a wave soldering device was not applying enough solder or a brittle solder at that) then maybe the whole problem is the solder joints and the caps are only a secondary issue. Time will tell.

Lon Allen - 92 Q45t with a working A/C readout

Thanks to Deesolballs for saving this bit of information. Hopefully we can sort through all the old board posts someday and create an index of help tips. If anyone is interested, I would be willing to help transcribe and sort.

firedaneMedina, Ohio

AZQ45
Posts: 87
Joined: Sat Jul 27, 2002 10:12 am
Car: Q45, G35, My 3 sons, hockey, snowmobiling (when I can)

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No way I can remove the unit right now...summer in AZ. Plug and play or nothing. I can still work it fine wihtout seeing it.

rod_ontario
Posts: 38
Joined: Thu Aug 08, 2002 5:37 pm

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The circled region is the area that I re-soldered and the square area denotes the portion of the board that had extreme electrolytic seepage. This caused the unit to go into the test mode when the weather was very humid.The arrow points to the circuit that I think is the culprit for the units display problem.



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