1994 c1500 - clicking noise from heater - Page 2

crabtruck · 12-01-2007, 06:49 PM

Pretty sure that's a great pic of the resistor on left and the blower relays on top.

teemsta · 12-02-2007, 08:37 PM

I just noticed that when I turn the wheel left the clicking gets louder under the glove comp area, and when I turn right and gets softer. strange because it goes away when I turn off the the climate control or blast the fan to high.

barcode27 · 08-06-2008, 09:08 AM

I suddenly started having this same problem with my '94 K5 Blazer. I removed the glove box liner and went searching for the recirculation actuator, but no luck. The only actuator I saw was on the far left side in there, but I'm pretty sure it was the temperature blend actuator and not the recirc (I watched it move while I adjusted the temp control). I felt around a little bit after turning the ignition on and off, and it seems like the thumping is coming from somewhere very deep in the ductwork. My next step was to remove the ECM module to see if the actuator was hiding underneath there. No luck.

Is there a specific place that someone can recommend to start looking for this thing? Any other clues such as what the part itself actually looks like or what color wires go to it would help as well. This is starting to drive me crazy! Thanks guys.

sammyhart · 08-29-2008, 03:19 AM

Just stopped my noise. There is a fresh air motor actuator located close to the firewall and very close to the blower motor ( attached to the blower motor duct) on the passenger side. It is about 6 inches from the floor on the left side of the blower motor. You can see it if your head is on the floor board looking up and back to the fire wall.
You can turn on the ignition and feel it as it clicks. You do not have to have the glove box out, you can't see it through this opening. You can replace the motor actuator or, I simply snipped the small wire that goes to the top of the actuator motor. Be carefull not to cut the main computer harness wires (they are much larger) that goes to the engine compartment, the computer wires are just under this motor. If you have the glove box out as I did you can tug on the small wire and see it from above through the glove box opening, this is where I snipped the wire (actually I think it was 2 very small wires in the same shielded cover) to make it easier to reconnect later.

hotrodpc · 09-02-2008, 01:25 PM

Thanks for the responses here. I will use this info on my dads 94. It has the exact same issue on the passenger side, when he turns the key off or on, or turns the AC off or on. I was certain it was the fresh air vent door actuator, but not certain exaclty how to get to it or where it was. Just a PITA noise is about all it is. It is not fan blades hitting anything as suggested above.

barcode27 · 09-02-2008, 07:48 PM

Does anyone know where to get this replacement part? I checked Rockauto and they only seem to have the temperature and mode door actuators.

bradrhale · 09-03-2008, 04:48 PM

i buy them at autozone all the time due to chevy is not the only one that used this particular actuator.

sammyhart · 09-07-2008, 07:15 PM

I think the autozone part # is 604-103 made by Dorman. Its about $60.00

08-29-2008, 03:19 AM	#14
sammyhart Junior Member Join Date: Aug 2008 Location: greenville sc Posts: 2	1993 clicking heater noise Just stopped my noise. There is a fresh air motor actuator located close to the firewall and very close to the blower motor ( attached to the blower motor duct) on the passenger side. It is about 6 inches from the floor on the left side of the blower motor. You can see it if your head is on the floor board looking up and back to the fire wall. You can turn on the ignition and feel it as it clicks. You do not have to have the glove box out, you can't see it through this opening. You can replace the motor actuator or, I simply snipped the small wire that goes to the top of the actuator motor. Be carefull not to cut the main computer harness wires (they are much larger) that goes to the engine compartment, the computer wires are just under this motor. If you have the glove box out as I did you can tug on the small wire and see it from above through the glove box opening, this is where I snipped the wire (actually I think it was 2 very small wires in the same shielded cover) to make it easier to reconnect later.

09-07-2008, 07:15 PM	#18
sammyhart Junior Member Join Date: Aug 2008 Location: greenville sc Posts: 2	Air actuator noise I think the autozone part # is 604-103 made by Dorman. Its about $60.00

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12-01-2007, 06:49 PM	#11
crabtruck Senior Member Join Date: Jul 2007 Posts: 1,464	Pretty sure that's a great pic of the resistor on left and the blower relays on top.

12-02-2007, 08:37 PM	#12
teemsta Full Member Join Date: Feb 2007 Posts: 42	I just noticed that when I turn the wheel left the clicking gets louder under the glove comp area, and when I turn right and gets softer. strange because it goes away when I turn off the the climate control or blast the fan to high.

08-06-2008, 09:08 AM	#13
barcode27 Junior Member Join Date: Aug 2008 Posts: 2	I suddenly started having this same problem with my '94 K5 Blazer. I removed the glove box liner and went searching for the recirculation actuator, but no luck. The only actuator I saw was on the far left side in there, but I'm pretty sure it was the temperature blend actuator and not the recirc (I watched it move while I adjusted the temp control). I felt around a little bit after turning the ignition on and off, and it seems like the thumping is coming from somewhere very deep in the ductwork. My next step was to remove the ECM module to see if the actuator was hiding underneath there. No luck. Is there a specific place that someone can recommend to start looking for this thing? Any other clues such as what the part itself actually looks like or what color wires go to it would help as well. This is starting to drive me crazy! Thanks guys.

09-02-2008, 01:25 PM	#15
hotrodpc Senior Member Join Date: Jul 2008 Posts: 108	Thanks for the responses here. I will use this info on my dads 94. It has the exact same issue on the passenger side, when he turns the key off or on, or turns the AC off or on. I was certain it was the fresh air vent door actuator, but not certain exaclty how to get to it or where it was. Just a PITA noise is about all it is. It is not fan blades hitting anything as suggested above.

09-02-2008, 07:48 PM	#16
barcode27 Junior Member Join Date: Aug 2008 Posts: 2	Does anyone know where to get this replacement part? I checked Rockauto and they only seem to have the temperature and mode door actuators.

09-03-2008, 04:48 PM	#17
bradrhale Moderator Join Date: Apr 2006 Location: Texas Posts: 2,744	i buy them at autozone all the time due to chevy is not the only one that used this particular actuator.