A/C Blower Problem - Please Help!

4516 Views 8 Replies 5 Participants Last post by richardtosh, Oct 13, 2009

keithe1

Discussion Starter · Oct 20, 2003

I just inherited a 1988 Cadillac DeVille from a late Uncle. The car has 108k miles, but has only been driven 6k miles over the past several years. Other then being filthy it runs great and is in good shape. The only real problem is that I cannot get the a/c to blow through the vents. Its cold and the fan motor will go from low to high, but won't come out the dash vents! Very frustrating in South Florida. Also, the radio worked today, but now will not come on. I also noticed the antenna did not go up either.

Any help would be appreciated as this is my first Cadillac, let alone GM product. The more specific the better as I will try to fix both myself. Thanks in advance!!

Keith.

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Katshot

· #2 · Oct 21, 2003

Welcome aboard,
The symptoms you describe would suggest that there is no vacuum getting to the A/C programmer since the default is generally to send air to the defrost vents (sometimes the bottom heater vents too). I would check the line from the vacuum source and/or the vacuum reservoir under the hood. On your car, I believe the reservoir is located on the cowel area and looks similar to a black cube. Okay it's not exactly square but it's close.

It may also be a ball or capsule-shaped black plastic piece under the front end. It's a dead give away since there's at least one vacuum line going to it and nothing else. Anyway, if you verify there's vacuum getting to the programmer (behind the glove box), then you'll need to troubleshoot it next. If this is the case, the diagnostic procedure is quite a bit more involved so you'll want to let me know so I can email some info to you rather than post it here.

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keithe1

Discussion Starter · #3 · Oct 21, 2003

Thanks, Kevin.

I'll check it out.

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carnut

· #4 · Oct 22, 2003

i agree with katshot re: vacuum supply. re: the radio, ck the " BODY" fuse for being burnt . an open, blown body fuse would render the memory section of radio inop. also if blown, look for tin foil or coins in all the ash trays and lighter sockets, thats usually what shorts the fuse. usually the power door locks also do not work. body fuse is yellow, 20 amp. hope this helps, Bill. p.s. just thought of something else to ck. look under the dash ash tray assembly for a bare wire to the lighter. as the ash tray is slid in and out, the wires are flexed. sometimes short against the ash tray metal.

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jdp6000

· #5 · Nov 26, 2003

My problem is a little different. I have a 1994 deville. When you first turn the heat on it may or may not work. When you start driving it sometimes all of a sudden it goes on. Once it turns on I have noticed excelerating causes the blower to turn off. Its almost like the engine is sucking the electricity out and there is none left for the blower.

Any ideas???

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carnut

· #6 · Nov 26, 2003

You Stated When You Turn The Heater On? I Presume You Shut The Climate Control System Off And On? The System Is Designed To Heat And Cool The Car By You Setting The Temp Display Somewhere Around 72/75 Degrees And Setting It To Auto. If You Are Running The Temp Display Up For Winter And Down For Summer, That Will Delay The Operation Of The In Car Temp Sensor. Try Leaving The System Alone For A Few Days To Verify Normal Operation. You Also State The Blower Delays. The Blower Is Designed To Delay Until Coolant Temperature Goes Above A Certain Thresholdthen When The Fan Comes On, It Will Blow Warm Air If Needed Based On In Car Temperature. In The Summer The Fan Does Not Delay Because Its Hot In The Car And The System Is Designed To Cool As Quickly As Possible. The Question About The Fan Shutting Off On Acceleration Is Probably Vacuum Related. When It Shuts Off Again, Feel The Defroster Vents, If All The Air Is Coming From There, Then You Have Weak Vacuum Supplied To The Dash. Ck The Vacuum Source Hose From The Engine. I've Also Noted That Some People Shut The Climate Controls Off As Well As The Radio Prior To Shutting Off The Engine. That Is A Complete Waste Of Energy. When The Engine Is Being Restarted There Is No Power Supplied To The Radio Or Climate System Until The Key Is Released. I Think We Got This Habit From Our Grandfathers! Good Luck, Sorry For The Rant.

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jdp6000

· #7 · Nov 26, 2003

carnut said:
You Stated When You Turn The Heater On? I Presume You Shut The Climate Control System Off And On? The System Is Designed To Heat And Cool The Car By You Setting The Temp Display Somewhere Around 72/75 Degrees And Setting It To Auto. If You Are Running The Temp Display Up For Winter And Down For Summer, That Will Delay The Operation Of The In Car Temp Sensor. Try Leaving The System Alone For A Few Days To Verify Normal Operation. You Also State The Blower Delays. The Blower Is Designed To Delay Until Coolant Temperature Goes Above A Certain Thresholdthen When The Fan Comes On, It Will Blow Warm Air If Needed Based On In Car Temperature. In The Summer The Fan Does Not Delay Because Its Hot In The Car And The System Is Designed To Cool As Quickly As Possible. The Question About The Fan Shutting Off On Acceleration Is Probably Vacuum Related. When It Shuts Off Again, Feel The Defroster Vents, If All The Air Is Coming From There, Then You Have Weak Vacuum Supplied To The Dash. Ck The Vacuum Source Hose From The Engine. I've Also Noted That Some People Shut The Climate Controls Off As Well As The Radio Prior To Shutting Off The Engine. That Is A Complete Waste Of Energy. When The Engine Is Being Restarted There Is No Power Supplied To The Radio Or Climate System Until The Key Is Released. I Think We Got This Habit From Our Grandfathers! Good Luck, Sorry For The Rant.

Thanks for the reply. I just went for a run on the highway. I set the defrost on "on". Heat at 23 celius (72 degrees). I tried both Econo and Auto. Speed set at "high". I felt heat rising from the dash vent BUT the blower was not come on.

I got off the highway and came to a stop. The blower came on. I felt the vent on the dash.I could hear the blower. It sounded obstructed. Almost like the vent was not open. I accelerated and the blower stopped running. I drove home...about 15 km the motor did not come on while on the highway. Once I got off the highway and came to a stop the blower cycled on then off again.

I should tell you I just got this car. The blower motor looks new. It seems obvious the previous owner was trouble shooting this. Screw have been removed form the cowling under the hood around the main fuses. I can also see that the screws that hold the glove box had at one time been removed. i take it the vaccum control mechanism is behind the glove box...I can hear something switching their. As far as you know are there electrical connections to the vaccum contol behind the glove box? Does it make sense that if vaccum pressure is lacking the system would shut down?

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jdp6000

· #8 · Nov 27, 2003

jdp6000 said:
Thanks for the reply. I just went for a run on the highway. I set the defrost on "on". Heat at 23 celius (72 degrees). I tried both Econo and Auto. Speed set at "high". I felt heat rising from the dash vent BUT the blower was not come on.

I got off the highway and came to a stop. The blower came on. I felt the vent on the dash.I could hear the blower. It sounded obstructed. Almost like the vent was not open. I accelerated and the blower stopped running. I drove home...about 15 km the motor did not come on while on the highway. Once I got off the highway and came to a stop the blower cycled on then off again.

I should tell you I just got this car. The blower motor looks new. It seems obvious the previous owner was trouble shooting this. Screw have been removed form the cowling under the hood around the main fuses. I can also see that the screws that hold the glove box had at one time been removed. i take it the vaccum control mechanism is behind the glove box...I can hear something switching their. As far as you know are there electrical connections to the vaccum contol behind the glove box? Does it make sense that if vaccum pressure is lacking the system would shut down?

I figured it out. It was the electrical connection at the blower. Its real sensitive. I bent the prongs a bit. Taped the plug together real tight and it has been working fine.

Thanks,

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richardtosh

· #9 · Oct 13, 2009

My blower quit. Frank Kent Cad Dealership fixed it. Also, had tune up.
Under the hood where the blower motor is, they knocked a hole in the
plastic housing and did not tell me. It's bigger than a "knockout" panel, so they must have hit it with a wrench or something, possibly when they were changing the plugs, since it's all at the rear of engine. So, we sensed motor fumes inside the car and I just thought it was from work they'd done. They did not tell me they had left this opening to the engine compartment. So, I think we're getting fumed....maybe to death! I'm taking it back tomorrow. Should the plastic housing be replaced---looks like a really big job like it's the whole firewall , or should the hole just be patched. I have duct tape on it now. I thought I only had to do that on my Ford!!! Am I getting fumes? Are they responsible? They were so courteous when they delivered the car back to us but failed to tell us they'd damaged the whateveritis they did. I hope this is clear. I think they owe me. Thanks

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