Heater Problem 03 Silverado

chvymtl3 · February 27, 2008

I have a 2003 Silverado with the manual slide (Driver/Pass) Heater Control Unit. If I have the heat on high on both slides, I get minimal heat. If I slide the pass side to cold, the driver side is hot and vice versus. I did a search on the forum and saw this post http://www.gm-trucks.com/forums/index.php?...=heater+problem

I now this is for a 2001 truck. Were there any real changes in the system between 2001 and 2003?

Secondly, the volume of air on the drivers side is probably half of what the passenger side output. Any ideas?

Thanks

minibike132 · February 27, 2008

Check the bulliten in the middle of the page "1999-2007 silverado classic"

chvymtl3 · February 27, 2008

I had looked at the tech section. The first one only list for the 01-02 with automatic control (mine has the manual control) and the second one if for 04-06 with a ticking noise and DTC's. I don't have clicking noises and have checked DTC's with my Hypertec Progammer and no DTC's.

chvymtl3 · February 28, 2008

I didn't mean look in the tech wikki look at the post that you linked to in your first post. MCUEVA attatched a bulliten about half way down the page. Give that a look.

Ok, I see the one you are referring to # PIT4427

But I have a question in regards to it:

Connect a 3 amp fused jumper wire between the actuator control circuit and the 5 volt reference circuit of the actuator connector.
Remove the jumper wire and actuator connector when the actuator is at the center position.
If the actuator doesn't move in step 2. Try installing the jumper wire from control circuit and the ground circuit of the actuator

I have not pulled this apart yet, but how will I know what wire the control circuit is? I know I can use a VOM to measure the 5V reference and find ground. Are there only three wires on the actuator? I know i should look before I ask, but I am at work and can't run out and tear the trcuk apart.

Thanks

minibike132 · February 28, 2008

I didn't mean look in the tech wikki look at the post that you linked to in your first post. MCUEVA attatched a bulliten about half way down the page. Give that a look.