Heater controls question

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Feb 28, 2015 | 11:00 PM

Terry J

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From: Brighton TN

Heater controls question

Got a 90 vette this weekend and one of the small problems ive notice is occasionally when you start the car the heater turns on full heat full speed and there are lines on the unit instead of numbers. If you shut it off and start the car back up it works right most of the time. occasionally takes a couple tries. Any Ideas?

Mar 1, 2015 | 05:37 PM

Terry J

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From: Brighton TN

Any ideas oh great and wonderful guru's?

Mar 1, 2015 | 05:45 PM

Nowhere Man

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I take it you have the electric controls. If so there are plenty of articles out there to repair them

Mar 1, 2015 | 05:51 PM

Cliff Harris

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From: Anaheim CA

Use the HVAC system diagnostics to find out what is happening:

Mar 1, 2015 | 06:28 PM

Terry J

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Joined: Sep 2010

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From: Brighton TN

Sorry. Yes i have the electronic controls. I watched the videos on repairing them but everything I read was for the buttons not working intermittently not the whole system locked up upon startup so I thought this may be different. I will run the diagnostics to see if it gives me a code.

Mar 1, 2015 | 08:01 PM

Terry J

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From: Brighton TN

Looks like just like the video I have a code 3. My sensor was not unplugged however.. LOL so tomorrow Ill break out the multi meter and see if its an open circuit or not. Thanks for the help guys!! I hope replacing that sensor resolves my issue.

Mar 2, 2015 | 11:56 AM

vettespecial

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From: Tennessee

Quote:

Originally Posted by Terry J

My 90 does the same thing only in cold tempiture display is blank except for line. It would not work at all until I removed took it apart cleaned switch contacts with isopropyl alcohol. Works fine unless it's cold, gonna live with it
For now I believe it's the control head.

Mar 2, 2015 | 12:04 PM

Terry J

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Joined: Sep 2010

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From: Brighton TN

Quote:

Originally Posted by vettespecial

Im going to do the same thing to mine after I sort out the Outside Temp sensor open error. I checked it to see if it was plugged up and it was so Im going to Put an ohm meter on it tonight to see what we got and go from there. Just thought it was really weird it going to full hot and full fan when you start it then if you shut it off an start it back it works ok. Oh well gives me something to tinker with. LOL