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CHRIS ZAPANTIS
CHRIS ZAPANTIS,
Category: Classic Car
Satisfied Customers: 159
Experience:  AUTO TECH at G&M EXXON
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Buick LeSabre Limited: 1979 Buick LeSabre with automatic climate

Customer Question

1979 Buick LeSabre with automatic climate control. I cannot get the blower to go on. After I washed the engine it started working for a while then quit again, probably a bad idea because now the GEN light is on dimly all time but thats besides the point. I bought the car and I couldn't get the automatic climate control blower motor to work since I bought it except the one time it worked for quite some time. Also I jumped the blower motor and it fires up strong and isn't noisy. Also I am familiar with this system. It should have the blower fan running even on the off position. It has no fan at all no matter what position I put it in. I did get the blower fan to come on tonight for a short time in off position but when I tried to turn on the climate control it quit again. I have experience using a similar system I had on my old 1975 Buick Riviera. But this LeSabre is really annoying because I don't get blower fan.
Submitted: 7 months ago.
Category: Classic Car
Customer: replied 7 months ago.
I would like to know the procedure to get the blower running from the factory service manual. I am not sure what to try or how to go about it.
Expert:  CHRIS ZAPANTIS replied 7 months ago.
Hello Im Chris and I will try to assist you. Let me know when you are on.
Customer: replied 7 months ago.
I'm here
Expert:  CHRIS ZAPANTIS replied 7 months ago.
Just the blower motor is not working? All other aspects of it are fine?
Customer: replied 7 months ago.
Yes it cycles fine to the positions and I can feel the air conditioning. The blower motor worked for a little bit but then stopped. I tested the motor by jumping it to the battery and it fires right up and smooth. When I washed under the hood is when I thought it worked again but soon after stopped working the next day.
Expert:  CHRIS ZAPANTIS replied 7 months ago.
Ok. have you replaced your blower motor resistor?
Customer: replied 7 months ago.
Also I can hear the relay kick in when I switch the controller to auto.
Customer: replied 7 months ago.
No I have not replaced the blower motor resistor. I pulled it out and it looks fine. Is there a way to test?
Expert:  CHRIS ZAPANTIS replied 7 months ago.
Ide check for a good ground on the motor and then replace the blower motor resistor. 90 percent of the time its either blower or resistor.
Expert:  CHRIS ZAPANTIS replied 7 months ago.
do you have power at the motor?
Customer: replied 7 months ago.
Ok I think I'll jump the ground to a more direct ground. The wire looks flimsy. But the blower motor resistor is original but not burned up or anything.
Customer: replied 7 months ago.
I checked and I have voltage at the motor from the purple wire of 12 volts when I turn on the defrost. But I think no amperage. Although I don't know how to test that.
Expert:  CHRIS ZAPANTIS replied 7 months ago.
you have 12 volts at the motor?
Expert:  CHRIS ZAPANTIS replied 7 months ago.
thats with the switch on high?
Customer: replied 7 months ago.
I believe I did. I used my voltmeter and turned on the defrost. Then I used the multimeter and put one probe in the purple connector and 1 probe to the ground wire. I believe I got over 12 volts.
Customer: replied 7 months ago.
Yes on defrost it is supposed to be on high as I remember.
Expert:  CHRIS ZAPANTIS replied 7 months ago.
ok and the motor doesnt run?
Expert:  CHRIS ZAPANTIS replied 7 months ago.
by what you are telling me the motor is bad
Customer: replied 7 months ago.
No the motor won't run. But the motor runs fine when I jump it.
Expert:  CHRIS ZAPANTIS replied 7 months ago.
are you close to the car?
Customer: replied 7 months ago.
Its downstairs in my parking spot. I have to leave to see it. But maybe I can answer on my phone.
Expert:  CHRIS ZAPANTIS replied 7 months ago.
you have a test light?
Customer: replied 7 months ago.
I have one meant for stereos that plugs into the cigarette lighter. But I think I should get an old school one because I don't understand how to use that one.
Customer: replied 7 months ago.
It has led lights with different colors when you touch wires.
Expert:  CHRIS ZAPANTIS replied 7 months ago.
get your voltmeter and let me know when you are there
Customer: replied 7 months ago.
Ok
Expert:  CHRIS ZAPANTIS replied 7 months ago.
can you measure ohms with your meter too?
Customer: replied 7 months ago.
Yes I can.
Expert:  CHRIS ZAPANTIS replied 7 months ago.
ok
Customer: replied 7 months ago.
Ok I'm here
Expert:  CHRIS ZAPANTIS replied 7 months ago.
i need with the blower motor plugged go in through the back voltage at purple wire
Expert:  CHRIS ZAPANTIS replied 7 months ago.
make sure the key is on
Customer: replied 7 months ago.
Ok touched the back of purple wire and touch other side to the battery ground and got 12.5 v
Customer: replied 7 months ago.
It's on defrost setting
Expert:  CHRIS ZAPANTIS replied 7 months ago.
ok good. do you have a long wire we can use as a ground?
Customer: replied 7 months ago.
Yes I do
Expert:  CHRIS ZAPANTIS replied 7 months ago.
jump the ground (black wire) to the battery negative.
Expert:  CHRIS ZAPANTIS replied 7 months ago.
this is at the motor
Expert:  CHRIS ZAPANTIS replied 7 months ago.
I guarantee you the motor will spin.
Expert:  CHRIS ZAPANTIS replied 7 months ago.
unless its bad
Expert:  CHRIS ZAPANTIS replied 7 months ago.
what happened?
Customer: replied 7 months ago.
Did not work with purple positive hooked up. So I jumped direct to the battery and fires up no problem. Weird.
Expert:  CHRIS ZAPANTIS replied 7 months ago.
its not possible
Customer: replied 7 months ago.
Just checked again. Purple wire says 12.5 volts but no motor spinning. Only when I jump it. That's why I'm wondering about amps or something else.
Expert:  CHRIS ZAPANTIS replied 7 months ago.
it cant be this motor runs even on low amps. its law that volts = ohms x amps
Expert:  CHRIS ZAPANTIS replied 7 months ago.
did you try banging on motor?
Expert:  CHRIS ZAPANTIS replied 7 months ago.
is the blower switch inside on high?
Customer: replied 7 months ago.
Well I just tried banging the motor. Nothing. Only jumping makes it work. Maybe directly jumping gives it more power?
Expert:  CHRIS ZAPANTIS replied 7 months ago.
if you have 12 volts you have enough power
Expert:  CHRIS ZAPANTIS replied 7 months ago.
put the blower switch on low and tell me voltage on purple wire
Customer: replied 7 months ago.
Same 12.5 v on low fan
Customer: replied 7 months ago.
That's why I think the factory service manual might shed light how this thing operates.
Expert:  CHRIS ZAPANTIS replied 7 months ago.
ok so the resistor is shot. change it they are cheap
Expert:  CHRIS ZAPANTIS replied 7 months ago.
i know very well how it operates thats a very simple system
Customer: replied 7 months ago.
Ok I'll try a new resistor tomorrow and get back to you.
Expert:  CHRIS ZAPANTIS replied 7 months ago.
Great please rate me so I can get credit. Thank you and let me know.
Customer: replied 7 months ago.
There are 5 wires on the resistor. I touched each terminal to positive of the motor and nothing happened. Shouldn't one of them have power?
Expert:  CHRIS ZAPANTIS replied 7 months ago.
tell me exactly what u did
Customer: replied 7 months ago.
I pulled the wires off the resistor. It is a five terminal plug. I proved those wires with a voltmeter. 3 of them read full 12.4 volts. Other 2 almost nothing. I touched a jumper from the ones reading voltage to the motor and nothing happens. Motor only works jumped to the battery. Seems power is being limited within the system somehow.
Expert:  CHRIS ZAPANTIS replied 7 months ago.
change resistor
Customer: replied 7 months ago.
Ok I'll try but what I'm saying is if no power coming off the plug plugging into the resistor then how could any power come out? I pulled the wiring plug for the relay as well. One wire there gives me power to power the motor. I think it's the one which actuates the relay when the AC is turned on.
Customer: replied 7 months ago.
So weird. I'm getting voltage at the purple wire but doesn't work. If I jump it, it works. This must be something else.
Customer: replied 7 months ago.
I mean jumping the blower works.
Customer: replied 7 months ago.
This automatic climate control must be not allowing power through but only voltage.
Expert:  CHRIS ZAPANTIS replied 7 months ago.
im going to have to opt out. Maybe someone else can help you better.
Customer: replied 7 months ago.
I just thought of something. The relay has a big red wire and red white wire which are turned on by the relay. The relay clicks, but maybe it's faulty?
Customer: replied 7 months ago.
OK
Customer: replied 7 months ago.
How do I get someone else to help me?
Customer: replied 7 months ago.
Does anyone out there know how exactly the 1979 Buick LeSabre Limited with a 5.7L Buick X Vin engine with automatic climate control is wired up? Where would my problem be getting voltage at the blower but blower not spinning? Maybe no amperage? Does it go to the relay first then into the resistors? Or possibly the fan switch inside the programmer? My feeling may be a relay but I tested it and it appears to work, but can they fail halfway? I don't know. I'm hoping there is a GM Buick Automatic Climate Control expert from the 70's still out there.
Customer: replied 7 months ago.
Checked the relay just now. Tested operation, works fine, no resistance when made to click through the circuit. Relay clicks when AC or other settings turned on, when put back to economy or off it clicks off. However no power getting through to fan. One thing I noticed is there is only 4 wires coming to the connector to the relay when there 5 spaces. I don't know what this means but there is no fifth wire, the middle one which is the default one I guess. I don't know how this wires up and what to test or look for. Hopefully there is a GM mechanic out there with the full knowledge and the library of service manuals for this LeSabre limited. Please help guys. No one answering me.
Customer: replied 7 months ago.
I just checked the resistor unit and all looks fine there. I cleaned it up. All the resistors are not burned and there is continuity between all the terminals to varying resistances. The relay under the hood clicked when I turned on the ac but didn't click back like before. Wondering if that relay is the problem. Is there another relay or something else to look at? In the programmer I found that inside is the blower switch which completes the circuit to the blower motor. Maybe that thing is bad? I am at a loss here. Is there any old 70's mechanics with experience with getting this blower motor to blow?
Customer: replied 7 months ago.
Hello!
Customer: replied 7 months ago.
I'm going to take the programmer out and look at the fan switch. Need to know how this circuit works. Maybe switch is bad?
Customer: replied 7 months ago.
I took the programmer out and applied vacuum to the big vacuum thing and it moves the switch and arm. But when I hooked it up to the car and cycled the modes it didn't do anything. No movement. I don't know if it is supposed to. Anyone know?
Customer: replied 7 months ago.
Where are the old mechanics here? With factory manuals.

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