2000 GMC Savana HVAC

ESANTIAGO5600

MEMBER
2000 GMC SAVANA

I'm not sure if I explained my problem correctly the first time so I'll try again.
When the heat and Ac is in the off position and in either position hot or cold the rear vents continuously blows heat on low. If it is the actuator where is it located? Is there a seperate one from the rear seeing that the front works as it's supposed to? If I turn the Ac on it blows cold front and back like it's supposed to, it's only when I turn if off that the back stays on and hot. Thanks in advance.

5 Replies

JDL

MECHANIC
16,098 POSTS

Maybe something wrong with aux blower low speed relay?

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Thursday, March 27th, 2014 AT 8:47 AM

ESANTIAGO5600

MEMBER
6 POSTS

Thanks for the quick response. I'm not so concerned about the speed it blows but more concerned about why it consistently coming out of the rear vents when it is in the off position? When off in the Ac mode it produces hot air when it should be off, but when the Ac is in the on position it works as it is supposed to. Confused

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Thursday, March 27th, 2014 AT 9:11 AM

JDL

MECHANIC
16,098 POSTS

Our info shows three speed relays, if there is continuity on the load side of relay, no matter the speed, the blower motor will run. There are two circuits for a relay, the coil side of relay is usually the control side, controlled by hvac. The load side of relay, red wire in the diagram, hot all the time. Fused circuit, no control from hvac, hot all the time. When the relay is energized, that line with the arrowhead moves to the red wire terminal and voltage will flow to the blower motor. It's possible that relay arm got hung up on the voltage terminal? There are other possibilities.

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Thursday, March 27th, 2014 AT 9:31 AM

ESANTIAGO5600