No Heat coming from Rear Vents

[Booyahzman]

Hey all,

Hoping to get some help on an issue before I start tearing apart the rear heater or A/C unit. I've done a bit of searching and reading and have gained a lot of knowledge! Long story short, heat is not coming out of the rear vents. I had a problem where the front vent--specifically the driver side had an issue where it wouldn't cool and only stay on the heat mode. This ended up being an actuator that I replaced and everything was great afterwards! So I thought the same may be true of the rear vents (not switching from cold to hot).

First, I thought I'd checked the pipes coming up from underneath the truck and verified the "hot" one was indeed hot.

I pulled apart the rear to get at the actuators, then watched them as I switched between floor to ceiling vents and cold to hot. I could see on both actuators the gears turned according to what I set the system to blow. OK, not the actuators... I was really hoping that it would be an easy fix!

Upon looking around next I noticed that the air was coming out through the gear hole on the temp actuator. Thought that was odd. I pulled the temp actuator off and found where I expected something to be sticking out (that the actuator would be twisting) nothing was there but a hole. Looking inside the hole I don't see a lot. I'll likely have to remove the cover to see more.

So in summary, whatever the rear temp actuator turns appears to be broken off or removed. I'm now going into territory I haven't gone before and wondered if anyone could give me advice or a better screenshot of what I should be looking at or for.

Thanks!

 

[Doubeleive]

could be the blend door broke or came off, I think a door runs about $25 if it can be replaced separate. the fan is working?

 

[mals]

Sounds like a similar issue to what I found when I was troubleshooting my rear HVAC.

Take a look at my post about it, and the YouTube video that I link to.

http://www.tahoeyukonforum.com/thre...-maintenance-build-thread.98211/#post-1170488

 

[Booyahzman]

Great video, thanks @mals ! That's exactly what I fear happend too. I wonder if I can just replace the blend door or if I need to replace the whole unit.

 

[mals]

Great video, thanks @mals ! That's exactly what I fear happend too. I wonder if I can just replace the blend door or if I need to replace the whole unit.

I found a decent price on the whole housing that included both doors. I figured if I was pulling the entire housing to work on one of the doors I would just replace the entire unit so I wouldn't have to do it again when the other door or my repair failed.

 

[Booyahzman]

I found a decent price on the whole housing that included both doors. I figured if I was pulling the entire housing to work on one of the doors I would just replace the entire unit so I wouldn't have to do it again when the other door or my repair failed.

Where did you find the replacement housing part?

I have a good friend who works on GM vehicles at a dealership and gets me pretty good prices for parts and labor. I think I'll hit him up to see if he can get this part for me...

Sent from my SM-G930T using Tapatalk

 

[mals]

Where did you find the replacement housing part?

It was GM Part #88891577

I found a new old stock piece on ebay from a dealer that included free shipping.