99 GC Relay clicking when heat controls changed

[josephk300]

On a dual heater control, moving the temp control slides, or changing the panel settings dial is causing a rapid clicking sound to come from the interior fuse junction box. The fresh air vent is also not working - all air is being recirculated. Initiated a heater control diagnostic check, and problem is indicated by persistant flashing rear wiper and washer indicator lights. There is no loss of function for any heater control, other than fresh air vent. Ideas on what else to check to pinpoint problem would be appreciated.

[RIP]

http://www.allpar.com/fix/codes-climate.html

[josephk300]

Thanks for the link, but as I mentioned in the original post, I "intiated a heater control diagnositc test", which is what the Allpar site is describing. My original post is not answered by the reference to the Allpar link. Since the original post, I got the fresh air vent is working again. I took the actuator off and activated it by turning the fan on, and pushing the recirc button on the control panel. (The actuator is on the passenger side foot well. The electronic module you see when looking up is the fresh air/recirculate actuator). I ran it through several cycles (it goes about 1/3 of a revolution and stops). After reinstalling it and runnning the diagnostic routine (for the '99 the procedure is at the link above, and is listed as alternative #1). The diagnostic test (which is also the calibration procedure) still reports an error, as indicated by the simultaneous flashing of the Wash and Rear Wiper button. The clicking from the area of the inside fuse panel is still there as well. At least the fresh air vent is working which make a huge difference cabin smell and windows not fogging so readily.Would love to know what's making the relay go nuts.

[josephk300]

Following up on the clicking relay: Went to a repair shop, and they determined the relay that is clicking rapidly appears to be for the rear window defogger. Strange that moving the heater control temp slides would cause this to happen. Their best guess is that the heater contol board is the problem. I also found that switching on the rear defogger prevents any of the the heater controls to function (ie, moving temp slide control from cold to hot position for a warmed up engine doesn't produce heat - just cold air). Once I change out the heater control board, I'll another follow up.

[RIP]

We're all scratchin our heads even more now. Looking forward to the update.

[josephk300]

As promised, as follow up to the heater control - clicking relay problem. Found a replacement heater control matching the exact part number on e-bay. Put the unit in, and ran a calibration/test procedure (procedure can be found elsewhere on this forum, or at allpar.com). The test completed without flashing lights indicating a problem. Operated the controls and presto - no more clicking when moving the heat control slides or turning the panel control knob. There were dozens of these for sale in various configurations on e-bay. I wonder if that's an indication of how much these units are prone to failure. Keeping my fingers crossed that this unit holds out better than the one it replaces.