for the lunch crew... 
AC only blows on low??
Thread Starter
Burning Brakes
Joined: May 2006
Posts: 904
Likes: 0
From: Boynton Beach FL
AC only blows on low??
Hi All,
AC has always been great in my car until a couple days ago. Now I notice, even if I set the control to blow on '10' it only comes out on the 'low' speed. Still blows ice cold though. Any idea what to check first? Some sort of fan control relay, I've read on the forum? This is on a 1994.
Thanks,
John
AC has always been great in my car until a couple days ago. Now I notice, even if I set the control to blow on '10' it only comes out on the 'low' speed. Still blows ice cold though. Any idea what to check first? Some sort of fan control relay, I've read on the forum? This is on a 1994.
Thanks,
John
Pro
Joined: Mar 2005
Posts: 666
Likes: 0
From: Walton KY
With the car idling & A/C on, open the hood and "tap, tap, tap" the fan motor over on the passenger side in the engine compartment to see if it "frees" up the bearings.
Is it making any kind of noise? It shouldn't matter, but try switching between A/C and full heat.
In my Z71, my fan did the same and the fan bearing was making noise. I replaced the fan motor and although the noise was gone, I still had no other speed than 1 (out of 5). I then borrowed my buddy's truck and took his A/C controller out and put it in mine....same thing. I was then told that the $15 control module was probably the problem...and it was. I would start by trying to find the relay module between the fan and the switch.
Is it making any kind of noise? It shouldn't matter, but try switching between A/C and full heat.
In my Z71, my fan did the same and the fan bearing was making noise. I replaced the fan motor and although the noise was gone, I still had no other speed than 1 (out of 5). I then borrowed my buddy's truck and took his A/C controller out and put it in mine....same thing. I was then told that the $15 control module was probably the problem...and it was. I would start by trying to find the relay module between the fan and the switch.
Safety Car
Joined: Oct 2007
Posts: 3,816
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From: :45 minutes from everywhere / E-I-E-I-O
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Le Mans Master
Joined: Aug 2000
Posts: 8,838
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From: Australia
Le Mans Master
Joined: Jan 2006
Posts: 5,620
Likes: 206
From: Orlando FL
I would at least clean up the contacts on the C68 controller.
Clean the rear connector on the back of the unit. Just use a good contact, safe for plastic cleaner.
Disassemble the unit and clean the pins on the connector which connects both circuit cards together. They oxidize or corrode and cause many of the strange problems. It is also a good time the inspect the solder of the LEDs and buttons. Flickering lights or no response or delayed response are problems with these areas.
You can also measure the 10 steps of the motor control voltage. You can look at the input to it to see if it is correct to. That way you can determine if the module is working or need to look elsewhere.
Clean the rear connector on the back of the unit. Just use a good contact, safe for plastic cleaner.
Disassemble the unit and clean the pins on the connector which connects both circuit cards together. They oxidize or corrode and cause many of the strange problems. It is also a good time the inspect the solder of the LEDs and buttons. Flickering lights or no response or delayed response are problems with these areas.
You can also measure the 10 steps of the motor control voltage. You can look at the input to it to see if it is correct to. That way you can determine if the module is working or need to look elsewhere.
Thread Starter
Burning Brakes
Joined: May 2006
Posts: 904
Likes: 0
From: Boynton Beach FL
I would at least clean up the contacts on the C68 controller.
Clean the rear connector on the back of the unit. Just use a good contact, safe for plastic cleaner.
Disassemble the unit and clean the pins on the connector which connects both circuit cards together. They oxidize or corrode and cause many of the strange problems. It is also a good time the inspect the solder of the LEDs and buttons. Flickering lights or no response or delayed response are problems with these areas.
You can also measure the 10 steps of the motor control voltage. You can look at the input to it to see if it is correct to. That way you can determine if the module is working or need to look elsewhere.
Clean the rear connector on the back of the unit. Just use a good contact, safe for plastic cleaner.
Disassemble the unit and clean the pins on the connector which connects both circuit cards together. They oxidize or corrode and cause many of the strange problems. It is also a good time the inspect the solder of the LEDs and buttons. Flickering lights or no response or delayed response are problems with these areas.
You can also measure the 10 steps of the motor control voltage. You can look at the input to it to see if it is correct to. That way you can determine if the module is working or need to look elsewhere.
Any guesstimate on how much work it'll take to get to the back of the unit? Am I basically taking apart the entire dashboard?
Le Mans Master
Joined: Jan 2006
Posts: 5,620
Likes: 206
From: Orlando FL
Hears a short summery.
Got to take off the center trim (and in order) starting with the door for the center storage compartment. Loosen shifter plate, top A/C vent, remove trim plate around radio. Then just 2 screws and the unit pulls right out.
Having the right tools takes 15 minutes, another 1 to 2 hours to service the unit, and half hour to install. I would think the first time thru it will take twice as long.
Be careful and gentle, old plastic breaks real easy.
Got to take off the center trim (and in order) starting with the door for the center storage compartment. Loosen shifter plate, top A/C vent, remove trim plate around radio. Then just 2 screws and the unit pulls right out.
Having the right tools takes 15 minutes, another 1 to 2 hours to service the unit, and half hour to install. I would think the first time thru it will take twice as long.
Be careful and gentle, old plastic breaks real easy.
Last edited by pcolt94; Jul 23, 2008 at 08:36 PM.
