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1999 3.8 GT grand prix blower/fan problem

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PilotGuy20

New member
The problem started out where the air conditioning/heating blower motor would cut off for a few
seconds and then back on. It started to become progressivly worse happening more often and
for longer duration.

Also when the blower motor cut off the led for the airconditioning would also go off as well as
the led for the rear window defogger. The running lights would also go off. Also when this
electrical outage occurred if the headlights were turned on by the automatic daylight sensor they
would turn off but if I manually had the headlights on by the manual headlight switch the
headlights would stay on.:th_scratchhead:

The radio and engine were not effected by the electrical outages. I could also hear a click in the
dashboard when the electrical outage would occur and a click when it would come back on as if a
relay was tripping.

The problem has progressed to where 95% of the time that the airconditioning/heater blower
motor and the above mentioned electrical systems do not function at all if I have the blower set
on speeds 1-4. If I set the blower to speed 5 the blower consistantly works as well as all
electrical systems. As soon as I turn the blower to setting 1, 2, 3 or 4 the blower moter turns off,
I hear a click in the dashboard, the running lights turn off, rear window defogger does not work
and the airconditioning light goes off (the airconditioning compressor also cuts off). As soon as I
turn the blower switch to off or to posisition 5 everything comes back on. Of course, in off
posisition the blower moter does not run normally but all other electrical systems are
functioning.

The dealer checked the computer and it did not have any codes for any problem. The battery has
been replaced.

Gigling the blower switch or switching it between speeds 1-4 does not effect the problem as the
effected electrical systems will remain dead.

As I mentioned the Radio and engine has never been effected by the electrical outages.

It sounds like to me like a protection circuit activating like a circuit breaker and that the running
lights, blower motor, rear window defogger and airconditioning are on the same circuit?

Perhaps it is a short or a grounding problem? I'm not a mechanic, I'm a computer tech so I'm not
sure where to check for electrical connections or grounds if that is what I should be checking for?

Any ideas would be appreciated as no one else has any? The common element is the effected
electrical systems with the blower switch being the catalyst that causes it all. :th_scratchhead:
I also replaced the fan speed resister. HELP:th_scratchhead:
 


SuperSport said:
High possibility its the ignition switch flaking out on you.
Click to expand...

I don't really think so on this one. With the ignition switch, it is either off or on, from my experience. I have never heard of it going off and coming back on in the middle of driving it.

I would rather point to a loose wire or connection somewhere. And something like that is really hard to pin down.

I would start at the fuse panel and make sure everything is tight and clean.
 
I had a similar problem with my 2000. The blower worked fine on high but would slow on the other settings then quit all together. I replaced the resistor pack but it still didnt work. I found out my blower was junk also. After replacing both the resistor and the fan it worked fine. The resistor pack is located behind the glove box mounted on the firewall. The foreward screw is impossible to remove. I unplugged it and mounted the new one with velcro to a flat spot under the dash.
 


I agree with the majority. Start with the resister pack. And yes the front screw is damn near impossible to remove, I finally got it removed and wanted to look up the engineer that designed it that way and kick his A$$. Anyway... Start there.
 
Last edited:
I already replaced the resister pack. That was the first thing I went for. replaced it last week. Thanks for your input.
 
I would also think its your ignition switch. When I still worked as a mechanic, there was a guy who brought his GP in with the same issues and after some diagnostic work we found out that it was his switch and a relay.
 


For those whose fan starts to work intermittently on low speeds, Jerry Davis posted this on the GPML a while back:

quote:

I have a '97 GT that I bought new, so I've had my car on the road longer
than most of those in this group. That being the case, one can reasonably
expect equipment failure to show up sooner on my GP than on newer models.

One interesting failure is something called the "fan ignition switch." That
switch is a thick cluster of heavy and lesser wires, about 1.5 feet long,
with robust termination blocks on each end. One end also has geared,
mechanical components. This part installs under the dash on the drivers
side and up into the steering column.

You need to replace it when your A/C fan begins to operate intermittently.
For example, if you are driving and the fan simply stops, then restarts
while on any speed setting 1-4 (not on speed setting five setting until some
weeks later ,) your switch is failing. The problem will gradually become
worse, with the outage taking longer to recover, until you achieve total
failure.

There are actualy two parts that can cause this problem, and the second part
is called the resistor pack. That part connects directly to the blower
housing under the dash on the passenger side, and is about 24 bucks new from
GM. My fully functional pack was slightly burned on the circuit board, so I
replaced it.

The fan ignition switch was easy to replace, but it is awkward to install.
You will need typical small hand tools, plus an 8-inch or longer socket
extension. a torx male socket (T11, I think) and two torx female sockets
(T11 and T10.) I didn't know that until I had my steering column torn down,
and had to drive around the city with a skeletal column, wires dangling and
tools in the floorboard. No one sells female torx wrenches that small, so
you will have to buy two small standard wrenches. (Your 1/8th inch drive
sockets are way too big to fit the space you will have to work with.)

Sears has a perfect solution. Buy the 5/32nd and 1/8th size wrenches on the
2.5 inch steel stems. They look like small screwdrivers with the socket
permanently mounted at the end of a thin, steel stem. You will need the
small stem because you won't be able to remove the cowl above the steering
column, and its in the way.

The physical key slot on the primary ingnition switch is too big for the
upper steering column cowl to slide over, so you will have to raise the
plastic cowl as far as possible to access the two very, very small torx
screws holding the fan switch in place. The cowl will be stressed, so be
careful.

Also, you will have to cut and splice two wires due to being unable to
remove the upper steering column cowl. There is some magic part snapped
into a slot on the top of the column that you will not be able to reach,
which will have to be left there. Cut the two wires coming off it and
splice them to the two matching wires coming off your new part. There is a
small, odd shaped white plastic box attached to one end the two wires.
Nothing comes out of the little box, and there are no metal contacts on the
surface of it. Apparently, there is something inside the box that sends
some kind of signal/magnetism/charge through its housing to a receiver in
the steering column. Or not. Who knows?

The wires are very plainly marked, they match the new ones and there are
only two. You can't screw it up unless you fail to insulate your splices.
If you don't unsulate them well, then you can expect some really fun
problems later, and maybe even some fireworks in your lap as you drive down
the highway, impressing your woman with your technical prowess :)

That job takes about 1.5 hours, and the part is 56 bucks from Grand. GM
wants 98 dollars for it, and a shop will charge you around 300 dollars to do
it.



The tip about the Sears tools is definitely a life saver. The ignition switch part number is 26068757.

Okay, here's full directions with pictures -

1) Remove the lower panel beneath the dash. You should know how to do it by now.
s4.gif
2 phillips head screws.

2) Take out the two Torx bolts (size 25) under the steering column:

IMGP1456-vi.jpg


Pull out the tilt lever:

IMGP1457-vi.jpg


Push the lower cover towards the dash and down to disengage the clips:

IMGP1459-vi.jpg


3) Here's where the Sears tools come into play.

IMGP1460-vi.jpg


Or small female torx bits, if you have those. There's two screws holding on the top cover, one left, one right:

IMGP1461-vi.jpg


IMGP1462-vi.jpg


4) Disconnect the negative terminal from the battery. Now comes the tricky part. There's a small hole above the ignition, circled here:

IMGP1464-vi.jpg


Turn the key to "START", and push a small hex wrench in the hole to release the latch. It's pretty hard to get to, I used needle-nose vice grips to hold the wrench:

IMGP1466-vi.jpg


So after the latch is pushed down, release the key to the "RUN" position, and the whole key receptacle can be pulled out. IMPORTANT: Keep the key in the cylinder until you have reinstalled it and turned to the OFF position.

IMGP1467-vi.jpg


5) Now to use the other Sears tool. There's two screws on the ignition switch, circled here:

IMGP1470-vi.jpg


Press with a screwdriver on the left of this white plastic piece to press the tab, so the white part can be rotated out:

IMGP1472-vi.jpg


You'll have to disconnect an electrical connector from the solenoid that keeps the key from being removed. I have removed that solenoid, so I don't have pics of it. There may be some tie wraps to cut, also. Now we're free from the steering column:

IMGP1475-vi.jpg


5) Undo this wire harness clip:

IMGP1476-vi.jpg


Use a 7mm socket to loosen this bolt and separate the electrical connectors:

IMGP1477-vi.jpg


Pry between the parts of the connector so the two outer parts can be pushed forward and separated:

IMGP1481-vi.jpg


6) Now to operate on the internals of the switch! Pry the top off, you'll see some springs:

IMGP1484-vi.jpg


Pry this metal ring off:

IMGP1485-vi.jpg


Pry off the next cover, you'll see this:

IMGP1486-vi.jpg


Take out the pieces, and inspect. Here's our enemy, carbon!

IMGP1487-vi.jpg


Use some fine grit sandpaper to clean the pads on the metal bits, and the contacts on the switch side.

7) Put everything back together, basically just a reversal of the previous steps. Put the coil spring and the white "cam" in the top cover so the piece of the spring that sticks up is at 12 o'clock. The tab on the cam should be at about 9 o'clock. Place these parts on top of the lower assembly. The piece of the spring that sticks forward will not be in the correct location, you have to push it around to its correct position at about 4 o'clock, while holding the upper and lower parts of the switch together. Fun!
s11.gif


8) Test it out, enjoy the air blowing on your face at a low speed.
s4.gif
Congratulate yourself and partake of a frosty beverage.
 
I'm going to try this. I just haven't found the time to do it. Meanwhile I put a fused 10Amp wire and jumped from the power window fuse. Everything works fine now. The only side effect is that in the acc ignition mode the fan continues to opterate and also in the off position untill the door is opened.
 


Fixed our car, although somehow I couldn't get the main spring in right or something since it doesn't automatically jump back from start but at least everything else works.
 
My 2002 Grand Prix SE 3.1L has issues with the Fan Dial Knob. Blower motor doesn't blow air or heat while the Dial knob is at 1,2,3,4 but it does work only at the 5th dial knob position. Well for 3 months Dial knob stopped blowing on 1 & 2 dial setting, and 3,4,& 5 were fine. Now I lost all 1,2,3 & 4, but 5 dial knob setting works fine.. Would this be a Restistor Pack or Switch? Not sure where to start. Does anybody have ideas with my problem on my year and model car?
All help is greatly appreciated..
~Thanks for your time in responding.
 
Mine only worked on 5, until this morning. It just quit while I was driving. Haven't been able to check the motor yet. If the motor is fine is the problem with that ignition switch or could it still be something else. Its a '97 SE.
 
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