Infamous number 4 fan speed
07-20-2006, 08:03 AM
#1
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Infamous number 4 fan speed
For about a month or so I have had intermitant problems with my fan speed.
Switch on the A/C and no fan......go up to four and it blasts ice cold air....go down to three, two..one...and eventually it would work on another fan speed. Well, yesterday...crapped out and only works on four. My question is...Do I only need to look at the resistor pack? I took mine out and sprayed it a little with W/D 40...Put it back in...and still only number four fan speed works. Figured I would ask before 928 Specialists Opens and I order one without ordering something else with it. Thanks in advance
Switch on the A/C and no fan......go up to four and it blasts ice cold air....go down to three, two..one...and eventually it would work on another fan speed. Well, yesterday...crapped out and only works on four. My question is...Do I only need to look at the resistor pack? I took mine out and sprayed it a little with W/D 40...Put it back in...and still only number four fan speed works. Figured I would ask before 928 Specialists Opens and I order one without ordering something else with it. Thanks in advance
07-20-2006, 09:16 AM
#2
Team Owner
Hi it sounds like the resistor pack you might try removing the pack and try cleaning the contacts inside the pack cover then just plug in the pack to the wire harness without installing to test your work , dont let the blower fan run for long as the resistor pack is cooled by the blower fan blowing air past it in the duct
07-20-2006, 10:42 AM
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CAREFUL here.. the issue may not be the resistor pack. Check the fan to make sure it spins properly, you may have dirty or worn bearings in the fan motor itself. When you first start the fan on a low setting, 0 or 1, there may not be enough power to get the fan to spin, this will over heat your resistor pack and break it (ask me how I know this 
). Starting the fan on position 4, gives it enough power to spin up, and then moving to a lower speed it will work fine and the fan is already in motion.
At around $100 for the resistor pack you don't need to find out it was the motor after you kill the 4ohm wire and need to spend another $100.
). Starting the fan on position 4, gives it enough power to spin up, and then moving to a lower speed it will work fine and the fan is already in motion. At around $100 for the resistor pack you don't need to find out it was the motor after you kill the 4ohm wire and need to spend another $100.
07-20-2006, 11:45 AM
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It will not work at all today unless on the number four setting...Spun the fan by hand and it works fine...no resistance it seems....Another question....I took the pack out again and cleaned the points under the middle bar...and plugged it back in...and tried the fan...nothing again except for the 4 setting and the pack was not hot at all...not even luke warm....So..is the pack dead and is this normal...or do I lack power to the plug?
07-20-2006, 11:45 AM
#6
Race Director
To get to the resistor pack you need to pull the blower anyway.....chances are its really filthy.....give it a good cleaning and test it while its still out of the car......(same for resistor...or a new one)....heres a good link
http://members.rennlist.com/pirtle/svc.html
http://members.rennlist.com/pirtle/svc.html
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07-20-2006, 03:31 PM
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Brett... the resistors in the 'pack' are 4 coils of resistance
wire: 0.25, 0.4, 1, 2.5 ohms. Seems the usual failure is
for the .25 (& maybe the .4) coil to go open.
That 'bar' is an overheat protection, i.e. puts full speed
across the 'pack' to cool it down. It shouldn't touch
any coil but sometimes might.
G'luck.
p.s. it isn't necessary to remove the blower to get the
pack out. Apparently you've already checked the fan motor.
wire: 0.25, 0.4, 1, 2.5 ohms. Seems the usual failure is
for the .25 (& maybe the .4) coil to go open.
That 'bar' is an overheat protection, i.e. puts full speed
across the 'pack' to cool it down. It shouldn't touch
any coil but sometimes might.
G'luck.
p.s. it isn't necessary to remove the blower to get the
pack out. Apparently you've already checked the fan motor.
07-20-2006, 04:42 PM
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I ohm tested the pack and my numbers are all over the place. Also have problems with continuity...anyhow...928 specialists are sending me one for Saturday...Keep my fingers crossed till then....What else could it be if the new pack does not help?
07-20-2006, 06:00 PM
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Brett... The '89 schematic shows a fairly straight forward
setup. The fan switch, pack connector and wire harness
are all possibilities.
The fan could be mechanically ok but have electrical issues -
wiring, insulation, brushes, shorts.
G'luck.
setup. The fan switch, pack connector and wire harness
are all possibilities.
The fan could be mechanically ok but have electrical issues -
wiring, insulation, brushes, shorts.
G'luck.
07-20-2006, 06:28 PM
#13
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I echo that!! be very careful when you put the new pack in, if there is no air flow in the 0 or 1 position SHUT OFF IMMEDIATLY and ifgure out what is wrong or your will over heat the resistor pack very quickly. I rewired my fan switch so the position 0 is truely off and not really slow.
07-21-2006, 05:13 AM
#14
Nordschleife Master
This is interesting.
I havent had any AC issues to speak of, i briefly looked over this thread yesterday and didnt pay much attention to it as Ive never hada problems. Then tonight, after driving the car this afternoon when all was still good, Tonight i have the same issue, car blower is on in 1-4 but when i put on the AC the fan stops. Except when i have it on 4 when it goes full cold, and when it goes to defrost it blows full and cold through the dash vents.
Now i fooled around with the duct switching from floor to mix to dash, and it will blow on low fan speed on floor, but it goes through the dash? WTF! I set it to teh square which i always assumed was off, and if the fan is set to 1-3 it will blow correctly and cold but through the dash vent.
Any suggestions for that?
I will check out this resistor pack this weekend. My problem sounds very similiar with the difference of it working through the main dash vent but when its selected for floor. Anyone else had this specific problem?
I havent had any AC issues to speak of, i briefly looked over this thread yesterday and didnt pay much attention to it as Ive never hada problems. Then tonight, after driving the car this afternoon when all was still good, Tonight i have the same issue, car blower is on in 1-4 but when i put on the AC the fan stops. Except when i have it on 4 when it goes full cold, and when it goes to defrost it blows full and cold through the dash vents.
Now i fooled around with the duct switching from floor to mix to dash, and it will blow on low fan speed on floor, but it goes through the dash? WTF! I set it to teh square which i always assumed was off, and if the fan is set to 1-3 it will blow correctly and cold but through the dash vent.
Any suggestions for that?
I will check out this resistor pack this weekend. My problem sounds very similiar with the difference of it working through the main dash vent but when its selected for floor. Anyone else had this specific problem?