95 LeSabre Climate control display flashing

[sgunn27026]

We recently had a(n unaffiliated) shop replace the upper plenum intake manifold (which turns out the original had NOT had a compromised seal where they are reported to fail) and thermostat (which WAS the cause of the leak, could've replaced it myself and saved $230!). After getting the car back, the climate control display flashes after 10-15 seconds for a space of time, and temperature is no longer "controlled." I discovered a relay that became unseated, I popped it into place. There still seems to be an issue with the flashing display and "control" of temperature. I am sure that this is nothing more than an oversight by the mechanic and believe there to be a simple reset or disconnected connector. BTW: for those of you with similar yr/mk/mdl: we have over 240k nearly trouble-free miles on this wonderful machine, replacing only fuel pump (@230k; water pump (about 170k); and an air compressor, maybe 80k?; she's been awesome! Thanks for your help on this!

[HotZ28]

This is a typical problem when the battery cable is disconnected without first turning the climate control to the OFF position. Setting to the OFF position will allow all settings to go to the HOME position and should remain there until battery power is restored and the system restarted. Default start-up after a power loss, is the HOME position. If you disconnect the battery with the system ON, the settings remain in that position (whatever they were) so your calibration is off when power is restored. The control head does not have a memory back-up and it depends on battery power to remember previous settings during the next ignition cycle. You can try waiting for the system to recalibrate itself (usually after about 50 ignition cycles); or you can take it to a dealer and have the calibration reset using a Tech II scanner. Good Luck!

[sgunn27026]

Thanks, that certainly answers a previously mysterious instance when it miraculously recovered after a visit to Jiffy Lube. Follow-up question: can this be reset by just removing battery cables when climate control is "off"? If not, when you suggest "about 50 ignition cycles," is that specifically: turn key on, wait for climate control to cycle (35 seconds to "flash," 1 minute 8 seconds to discontinue "flashing"), then turn key off; or actually start the engine approximately 50 times allowing "unit" to cycle (aforementioned)?

[HotZ28]

The engine would need to be running for the system vacuum diaphragms to actuate, therefore allowing an attempt at recalibration. In addition, it would not hurt to turn the system OFF with a pause -- then ON several times while driving in an attempt to speed up the process. It may help & it might not, but worth trying! BTW, removing the battery cable after the fault is stored, would serve no purpose!