86944 fuse problem
08-10-2002, 10:07 AM
#1
Track Day
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86944 fuse problem
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User # 7187
posted 08-09-2002 11:03
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My 86 944 seems to have an electrical gremlin.
The # 17 fuse(heater) keeps blowing. Was wondering if anybody else has seen this one and are there some obvious things to check before I go ripping the wiring apart. The blower motor runs but none of the other heater controls work?
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TomH
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User # 197
posted 08-09-2002 11:19
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The fuse is blowing cuz its summer time and the car knows you don't need/want heat. Those Germans really knew what they were doing when they built these cars
Seriously, not sure where you should look first. Since the thermostat controls both cooling and heating, are you having any problems with the AC?
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Tom H - 88 944NA
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merlin
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posted 08-09-2002 11:25
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The A/C is not working I suspect the compressor is shot as there is no freon in the system
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Posts: 12 | From: NEW JERSEY | Registered: May 2002 | IP: Logged
User # 7187
posted 08-09-2002 11:03
--------------------------------------------------------------------------------
My 86 944 seems to have an electrical gremlin.
The # 17 fuse(heater) keeps blowing. Was wondering if anybody else has seen this one and are there some obvious things to check before I go ripping the wiring apart. The blower motor runs but none of the other heater controls work?
--------------------------------------------------------------------------------
Posts: 12 | From: NEW JERSEY | Registered: May 2002 | IP: Logged
TomH
User
User # 197
posted 08-09-2002 11:19
--------------------------------------------------------------------------------
The fuse is blowing cuz its summer time and the car knows you don't need/want heat. Those Germans really knew what they were doing when they built these cars
Seriously, not sure where you should look first. Since the thermostat controls both cooling and heating, are you having any problems with the AC?
--------------------
Tom H - 88 944NA
--------------------------------------------------------------------------------
Posts: 446 | From: Annapolis, MD | Registered: May 2001 | IP: Logged
merlin
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User # 7187
posted 08-09-2002 11:25
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The A/C is not working I suspect the compressor is shot as there is no freon in the system
--------------------------------------------------------------------------------
Posts: 12 | From: NEW JERSEY | Registered: May 2002 | IP: Logged
08-10-2002, 11:12 AM
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Three Wheelin'
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_When_ specifically does it blow? Just when you turn something specific on, or just at random times?
Jim, out to bleed the clutch once more... ah, the joyous, carefree life of a Porsche owner!
Jim, out to bleed the clutch once more... ah, the joyous, carefree life of a Porsche owner!
08-10-2002, 02:04 PM
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Burning Brakes
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Not necessarily. You only disconected the wire at the compressor. The wire it's self may be grounded to the chassis..remove the fuse. using an OHM meter check the the side of the fuse running out to the compressor to ground, with the wire still disconnected at the compressor. if it is open loop it is ok. if not the wire is melted or rubbed through some where.. HTH.
08-10-2002, 02:15 PM
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Lessee... AC clutch only gets power when you turn the AC on, so that's out anyway...
I'd look at the things that are on the heater fuse, and switched by the key (wow! big help that is!).
Blower fan, was it noisy or slow before this problem cropped up?
Climate control brain; easy to remove from dash & check for scorch marks, loose plugs, etc.
Climate control fan (under dash, near front end of glovebox.. see if it spins freely.
Now, I'm _not_ suggesting that you do this, but it's something I'd probably try as a troubleshooting method.. put a bigger fuse in _temporarily_ (add about 5 or 10 amps), to see how quick it blows; if it blows right away, you've likely got a dead short. If it lasts for a few seconds or longer, you've maybe more likely got a motor pulling high amps due to bad bearings or trash in the housing. But that's still a guess.
The short may be easier to find, using a multimeter to find circuit legs that have little or no resistance. I'd use that approach before trying to visually trace wires looking for problems.
Jim... errands to run...
I'd look at the things that are on the heater fuse, and switched by the key (wow! big help that is!).
Blower fan, was it noisy or slow before this problem cropped up?
Climate control brain; easy to remove from dash & check for scorch marks, loose plugs, etc.
Climate control fan (under dash, near front end of glovebox.. see if it spins freely.
Now, I'm _not_ suggesting that you do this, but it's something I'd probably try as a troubleshooting method.. put a bigger fuse in _temporarily_ (add about 5 or 10 amps), to see how quick it blows; if it blows right away, you've likely got a dead short. If it lasts for a few seconds or longer, you've maybe more likely got a motor pulling high amps due to bad bearings or trash in the housing. But that's still a guess.
The short may be easier to find, using a multimeter to find circuit legs that have little or no resistance. I'd use that approach before trying to visually trace wires looking for problems.
Jim... errands to run...
08-10-2002, 02:25 PM
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Burning Brakes
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I thought that the AC came on while trying to defrost the windscreen? causing a dry hot air? Or is this car not new enough for that? I trully do not know if this car does that. but a lot of newer cars do.