blinking A/C temp selector

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I have a 91 k1500 and after changing the compressor the temp select bar just flash's for a couple minutes and then stops, but if you try to change the setting it starts to flash again. any ideas? It worked ok before the comp change.
 

Schurkey

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I don't know what style of temp control panel the '91 uses.

If it's anything like my '88, the solder joints connecting the circuit board to the display break, and then the display goes dark until I poke my thumb into a certain spot on the display. Then it all comes back to life...for awhile.

I've re-flowed the solder twice now, and I need to do it again but have trouble working-up the ambition.
 

89RCLB

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Check the service manual.


Cell/section 62 in the 1988_ST-375-88-EDM_GM_CK_PICK-UP_TRUCK_ELECTRICAL_DIAGNOSIS_SUPPLEMENT addresses the issue you are having.
I don't see a supplemental for the 1989 to 1994's so I'm guessing that the 1988 supplemental covers all the way up to 1994.
 
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Thanks for the info, I do have the paper factory manuals for my 89 it covers 88 to 92 I think. I saw when doing an internet search something about grounding a green wire in the control head. Of course I can't find it again :( I'll see if I can find this in my books.
 

tsr2185

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I have a 91 k1500 and after changing the compressor the temp select bar just flash's for a couple minutes and then stops, but if you try to change the setting it starts to flash again. any ideas? It worked ok before the comp change.
Had the same issue on my 91, it was the temp actuator went bad. Behind the glove box on the left.
 
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