blown heater core - The 1947 - Present Chevrolet & GMC Truck Message Board Network

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.

**Boog** · 07-23-2012, 09:28 PM

I took it into the garage today. The guy looked at the antifreeze soaked carpet and said "well you're gonna need a heater core and a blend door motor on the left side". Ya THINK! What tipped ya off? " gonna run ya bout a thousand". Not! Wife said thinkadamngain!

It is supposed to be covered under warranty. We'll see.

**Boog** · 07-25-2012, 11:44 AM

Got the truck back. Wife's happy. They did the repair under warranty. Didn't want to but in the end they did. New left blend door motor and heater core + labor over $1200. I've never purchased an extended warranty on any of my vehicles before but this time I did. Good thing.

**Boog** · 08-26-2012, 03:13 PM

One month since the repair and the vent temp problem is back. It will be going back to the shop tomorrow.
Do you think it is only a door misalignment causing it to go warm on the one side? Is the door actuator adjustable?

clinebarger · 08-26-2012, 06:25 PM

Quote:

Originally Posted by Boog

One month since the repair and the vent temp problem is back. It will be going back to the shop tomorrow.
Do you think it is only a door misalignment causing it to go warm on the one side? Is the door actuator adjustable?

Its most likely the blend door is not fitting correctly in the plenum, Or its broke, Unfortunately the HVAC module will have to be removed again. & no the actuator is not adjustable

If they will not fix it....You can get by with "recalibrating" it when it acts up....

Place the ignition switch to the OFF position.
Remove the HVAC/ECAS fuse for a minimum of 10 seconds.
Install the HVAC/ECAS fuse.
Start the vehicle.
Wait 40 seconds for the HVAC control module to self-calibrate.

IMPORTANT: Do not adjust any controls on the HVAC control module while the HVAC control module is self-calibrating. If interrupted, improper HVAC performance will result.

**Boog** · 08-26-2012, 09:12 PM

Thank you CB.

**Boog** · 08-29-2012, 07:13 PM

They put on another left side actuator. Lasted one month to the day I think.
I wonder if the blend door is broken or misaligned how hard is it to replace it. This truck has the dual climate control. We've been getting some small bits of foam out of the vents on the right side. The right side functions correctly so I'm not too worried over the loss of door seal foam.
I just don't want to have to keep replacing this left side actuator.

07-23-2012, 08:37 PM	#1
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.

07-23-2012, 09:28 PM	#2
Boog laying low Join Date: Mar 2001 Location: Searcy, Ark. USA Posts: 13,684	Re: blown heater core I took it into the garage today. The guy looked at the antifreeze soaked carpet and said "well you're gonna need a heater core and a blend door motor on the left side". Ya THINK! What tipped ya off? " gonna run ya bout a thousand". Not! Wife said thinkadamngain! It is supposed to be covered under warranty. We'll see. __________________ Boog 69 Chevy stepside, 358/T350, 4.11 posi, 4.5/4 drop, rallys, poboy driver primer is finer 91 Chevy sportside, Tahoe, Yukon & GMC Crewcab All GM..'nuff said. I stand for the flag and kneel at the cross

07-25-2012, 11:44 AM	#3
Boog laying low Join Date: Mar 2001 Location: Searcy, Ark. USA Posts: 13,684	Re: blown heater core Got the truck back. Wife's happy. They did the repair under warranty. Didn't want to but in the end they did. New left blend door motor and heater core + labor over $1200. I've never purchased an extended warranty on any of my vehicles before but this time I did. Good thing. __________________ Boog 69 Chevy stepside, 358/T350, 4.11 posi, 4.5/4 drop, rallys, poboy driver primer is finer 91 Chevy sportside, Tahoe, Yukon & GMC Crewcab All GM..'nuff said. I stand for the flag and kneel at the cross

08-26-2012, 03:13 PM	#4
Boog laying low Join Date: Mar 2001 Location: Searcy, Ark. USA Posts: 13,684	Re: blown heater core One month since the repair and the vent temp problem is back. It will be going back to the shop tomorrow. Do you think it is only a door misalignment causing it to go warm on the one side? Is the door actuator adjustable? __________________ Boog 69 Chevy stepside, 358/T350, 4.11 posi, 4.5/4 drop, rallys, poboy driver primer is finer 91 Chevy sportside, Tahoe, Yukon & GMC Crewcab All GM..'nuff said. I stand for the flag and kneel at the cross

08-26-2012, 09:12 PM	#6
Boog laying low Join Date: Mar 2001 Location: Searcy, Ark. USA Posts: 13,684	Re: blown heater core Thank you CB. __________________ Boog 69 Chevy stepside, 358/T350, 4.11 posi, 4.5/4 drop, rallys, poboy driver primer is finer 91 Chevy sportside, Tahoe, Yukon & GMC Crewcab All GM..'nuff said. I stand for the flag and kneel at the cross

08-29-2012, 07:13 PM	#7
Boog laying low Join Date: Mar 2001 Location: Searcy, Ark. USA Posts: 13,684	Re: blown heater core They put on another left side actuator. Lasted one month to the day I think. I wonder if the blend door is broken or misaligned how hard is it to replace it. This truck has the dual climate control. We've been getting some small bits of foam out of the vents on the right side. The right side functions correctly so I'm not too worried over the loss of door seal foam. I just don't want to have to keep replacing this left side actuator. __________________ Boog 69 Chevy stepside, 358/T350, 4.11 posi, 4.5/4 drop, rallys, poboy driver primer is finer 91 Chevy sportside, Tahoe, Yukon & GMC Crewcab All GM..'nuff said. I stand for the flag and kneel at the cross



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