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clinebarger · 07-23-2012, 08:37 PM

You didnt mention they checked voltages, Only the parts that were replaced, I deal with trucks with your problem all the time, Alot are trucks the "dealer" couldnt fix. A good portion of them have the temp door "overtravel" intermittently. Reading the door posistion curcuit, Anything above 4vdc on full cold I consider overtraveling.
The only reason replacing parts seems to fix it....Is because disconnecting the battery resets the HVAC control head.

07-23-2012, 08:37 PM	#5
clinebarger Senior Member Join Date: May 2009 Location: Fort Worth, TX Posts: 6,370	Re: blown heater core You didnt mention they checked voltages, Only the parts that were replaced, I deal with trucks with your problem all the time, Alot are trucks the "dealer" couldnt fix. A good portion of them have the temp door "overtravel" intermittently. Reading the door posistion curcuit, Anything above 4vdc on full cold I consider overtraveling. The only reason replacing parts seems to fix it....Is because disconnecting the battery resets the HVAC control head.