Heater/AC controller on 1999 Chevrolet Silverado 1500

My 92 Chevy 2wd and 90 Chevy 4wd pickups both have digital heat/AC controller problems, which is apparently very common for those vehicles. Anybody got a cheap bypass/workaround/suicide solution? ;^(

by in Neosho, MO on September 29, 2009
3 answers 2 comments
ANSWER by on September 29, 2009
What type of work around? What is the goal here? Have you looked at used parts?
COMMENT by on September 30, 2009
I like your style, Dude. We have some good Chevy techs on the site, hopefully they will have some info. I checked and there is a technical service bulletin: #46-12-02 It refers to a "fix" for some of the problems with these units. I have no idea how well this works, but hope it helps. Here is what is says: Condition: a/c control head flashes, performs erratically or malfunctions. Cause: light surface corrosion on the control head terminals. Correction: remove the a/c control head and while holding the unit with the terminal cavity down (toward the floor) so no particles will fall inside on the circuit boards, polish the terminals on both sides of the cavity with a lead pencil pink eraser. do not use an ink eraser or other abrasive such as a small wire brush or sandpaper, etc. doing so will remove the terminal coating and degrade the contact surface. **performing this procedure, in many cases, will make replacing the control head unnecessary.** using this procedure in conjunction with the a/c circuit diagnosis found in the electrical diagnosis manual and especially before replacing a control head for any reason is recommended. after polishing the control head terminals, but before reconnecting, check for proper terminal contact as described in the applicable electrical diagnosis manual. if contact is good, apply dielectric grease (p/n 12345579) to the harness connector terminals. please do not apply grease to the control head. service parts information: p/n description qty 12345579 dielectric grease from tube as needed parts are currently available from gmspo.
ANSWER by on September 29, 2009
getting some use parts from ebay
COMMENT by on September 30, 2009
Good questions, bretb! Used heat/ac controllers from junkyards are nonexistent, and those early digital contollers are notoriously problematic, so any one I get is suspect. And since I've got two such beasts, I'm considering a totally different way of controlling the heat/ac, maybe a simple custom control solution from a classic car catalog, JCWhitney, etc.? Any ideas? Thanks for responding! thedudeabides
ANSWER by on May 27, 2011
found loose and burned conection behind glove box in a three wire conector where two red wires plug in.easy fix .
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