rear heater not blowin hot air, just cold

[bigbird189]

I have a 2003 GMC Yukon and the Rear air does not blow hot air. Just cold air. I sure there are threads about it but I personally cant find them. I have not looked at it other than knowing that it does not blow hot air. So answers please!!!thanks



___________________________________________________________________
2003 Yukon black, H.I.D Air intake, in process of Blacking out

 

[letsbangout]

I'm coming at this from knowledge of my own system (99 Yukon). Mine is always going to blow less-than-hot because it has no heater core back there, only an evaporator. Does yours have a temperature control? If not then it probably doesn't have a rear heater core either. I think the rear temp controls/heater cores didn't start until 07 right?

 

[chauncey0337]

I'm coming at this from knowledge of my own system (99 Yukon). Mine is always going to blow less-than-hot because it has no heater core back there, only an evaporator. Does yours have a temperature control? If not then it probably doesn't have a rear heater core either. I think the rear temp controls/heater cores didn't start until 07 right?

Not true. Rear heater core should be near the rear fan under the passenger side wheel well cover. Might just need a good flushing. Get truck up to running temp and feel the heater core hoses, they should both get pretty warm. If they both get hot, the blend door actuator might be bad.

 

[puckhead]

Not true. Rear heater core should be near the rear fan under the passenger side wheel well cover. Might just need a good flushing. Get truck up to running temp and feel the heater core hoses, they should both get pretty warm. If they both get hot, the blend door actuator might be bad.

So there is another heater core back there? Did not know that.

I have always been told it is a stuck blend actuator door.

have the same problem on mine. And now the front is not as hot as it used to be.

 

[bigbird189]

Not true. Rear heater core should be near the rear fan under the passenger side wheel well cover. Might just need a good flushing. Get truck up to running temp and feel the heater core hoses, they should both get pretty warm. If they both get hot, the blend door actuator might be bad.

I will try the hose method first. Also where is the blend door actuator located? Could I fix it myself? Thanks for the info.

 

[chauncey0337]

The blend door actuator should be located just downstream of the blower fan. I don't have much experience with it but it shouldn't be much different than the front.

 

[TWITCH101]

Try the flush....costs you one afternoon and about $15 worth of fluid....Mine had the same problem except the front was clogged up and not the back