Auxillary heaters in 1988 Carrera
02-05-2003, 04:20 PM
#1
Track Day
Thread Starter
Auxillary heaters in 1988 Carrera
I have the auxillary heater blowers,when I turn the rotary switch,nothing.Can the switch be bad,the inline fuses? The Bentley service book does not cover this topic. Thanks in advance.
02-05-2003, 04:37 PM
#2
Burning Brakes
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Check the fuses first, then...
It is common for the blowers themselves to sieze. They are located in the footwells, just forward of the doors.
It takes about 10 minutes to take one out. Check it to see if you can spin the fan with your fingers, probably not.
These cost about 75 I think, I replaced them on an 88 last year. If you can use a screw driver, do not pay anyone to do this job.
It is common for the blowers themselves to sieze. They are located in the footwells, just forward of the doors.
It takes about 10 minutes to take one out. Check it to see if you can spin the fan with your fingers, probably not.
These cost about 75 I think, I replaced them on an 88 last year. If you can use a screw driver, do not pay anyone to do this job.
02-05-2003, 05:40 PM
#3
Check fuses as Mark says. The main blower is located in the engine compartment and two blowers one on the right the other on the left in the foot wells. If any of the three are blown, none will work. The fuses for the heating system are located in the engine compartment on the left side under a black cover held in place by a wing nut. If the main blower motor in the engine compartment went, you would have heard it. Sounds like a cat fight in your engine. The foot well blowere will also make a bunch of noise just before going out. I have an '86 and a couple of months ago replaced the main blower ($150.00 for the blower) it took me about 1 hour to replace. Now the right foot well blower is going. I just ordered that blower from PerformanceMotorCars.com. They were the best price I could find - $106.00. It took about 2 minutes to take the three screws out on the right side of the foot well to check it out. When the part arrives, it sould take about 15 minutes to do the job. Pretty much plug and play.......
Good luck,
Jim
'86 911
Good luck,
Jim
'86 911
02-05-2003, 06:04 PM
#4
Track Day
Thread Starter
Mark
Thanks for the insight. One fuse was bad,changed it,motor worked okay, a little drag.The other motor is shot,time to find parts.You are right-simple job. Thanks again-My toes will be toasty going down the road.
Thanks for the insight. One fuse was bad,changed it,motor worked okay, a little drag.The other motor is shot,time to find parts.You are right-simple job. Thanks again-My toes will be toasty going down the road.
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Superdave312 (10-21-2020)
02-06-2003, 01:29 PM
#7
Donnie,
Just went through all this with my '88 too. What everyone else said, plus, if you need to replace the blower motor on the engine there's a great way to do it with a motor from Graingers - $22 vs $200+ for an oem motor (email me for more info). I also found that $105 was about the cheapest you're going to find a footwell motor (BTW, the motors and housings are identical on both sides, but there's a duct that screws on to the motor that is different from side to side).
I replaced the blower on the engine (see above) and cleaned and lubed the footwell motors. They worked fine for a few days then started making noise again, so I just pulled the fuses. I find that once the engine warms up I don't ever need the footwell blowers anyway (and it's really cold here), and when I used them with a cold engine I just got more cold air, so they seem to be kind of redundant. Maybe they help with defrost if that's an issue.
I thought about removing the rear blower and associated ductwork to clean up the engine bay, and replacing the footwell motors with new ones, but when the rear blower is unplugged, it cuts the power to the footwell blowers and if you jump the connector it blows the fuse. It's kind of a complicated system. BTW, there is also another relay in the trunk, just for the footwell blowers, that runs off the rear heater relay. At least that's what the wiring diagram looks like.
For the life of me, I can't understand why Porsche designed such a complicated HVAC system, especially for a car where weight is an issue. There is a total of 6 blower motors and all the associated ductwork, wiring, relays, and switches.
Good luck with it!
Just went through all this with my '88 too. What everyone else said, plus, if you need to replace the blower motor on the engine there's a great way to do it with a motor from Graingers - $22 vs $200+ for an oem motor (email me for more info). I also found that $105 was about the cheapest you're going to find a footwell motor (BTW, the motors and housings are identical on both sides, but there's a duct that screws on to the motor that is different from side to side).
I replaced the blower on the engine (see above) and cleaned and lubed the footwell motors. They worked fine for a few days then started making noise again, so I just pulled the fuses. I find that once the engine warms up I don't ever need the footwell blowers anyway (and it's really cold here), and when I used them with a cold engine I just got more cold air, so they seem to be kind of redundant. Maybe they help with defrost if that's an issue.
I thought about removing the rear blower and associated ductwork to clean up the engine bay, and replacing the footwell motors with new ones, but when the rear blower is unplugged, it cuts the power to the footwell blowers and if you jump the connector it blows the fuse. It's kind of a complicated system. BTW, there is also another relay in the trunk, just for the footwell blowers, that runs off the rear heater relay. At least that's what the wiring diagram looks like.
For the life of me, I can't understand why Porsche designed such a complicated HVAC system, especially for a car where weight is an issue. There is a total of 6 blower motors and all the associated ductwork, wiring, relays, and switches.
Good luck with it!
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02-06-2003, 07:07 PM
#8
Donnie, I replied to your email but it came back as a bad address, so I've coppied it here:
"Thanks for taking the time in addressing my problem on Rennlist.I took the motors from their housings, thinking I could substitute other 12 volt motors, but part of the housing is molded into the motor."
Yeah, the A/C condensor and evaporator motors and the fresh air motor are the same way.
"I might cut the shaft and remove the squirrel cage for more free flowing air."
I think like you can just pull the squirrel cage off the shaft.
"Please inform me as to which Grainger motor you used for the engine blower."
It's not too hard to do if you're a little bit handy. The Grainger motor is not a direct bolt-in, but it's still pretty simple.
The Graniger motor is number 2M197 - you can order it on their website for $22.73.
You need to pull the fan motor and housing off the engine, very simple. Remove the old fan motor and squirrel cage. You'll have to fabricate a round plate to mount the Grainger motor to the Porsche housing. I used a piece of .080" aluminum with three holes to mount to the housing, and then a larger center hole and two small mounting holes for the motor.
The Grainger motor has a 1/4" shaft, and the Porsche fan has a 5/16" hole. I found a perfectly sized bronze bushing at a hardware store - 1/4"
id, 5/16" od, 3/4" long, or you can make one from some 5/16" X .028 wall tubing. Then I drilled and tapped the boss on the fan to accept an allen-head set screw (sorry don't remember the size) to hold
the fan on the shaft. The shaft has a flat side, so if you also drill the bushing you can lock it on well. To gain access for the drilling and tapping, I removed one of the blades on the fan, and another on the opposite side to maintain balance. Assemble the motor to the housing, then position the fan correctly before you tighten it down. I also used some Loctite to be sure everything stays together.
The new motor housing is slightly shorter and slightly larger in diameter. It fits in the Porsche mounting cradle fine, but I changed to a
slightly longer bolt for the band clamp that holds it all together. Sorry, don't have any notes about the size - I think it was an 8mm metric, not sure about the length.
I snipped the wiring harness off the old motor and spliced it onto the wires from the new motor (black is ground on the motor, brown is ground
on the plug), so it plugs in like stock.
The whole job took about an hour and a half, and it would probably take 15 minutes to swap just the motor in the future. The Grainger motor is
made by Dayton and seems to be at least as good as the Porsche part. Working fine so far!
Good luck with it!
Dave
"Thanks for taking the time in addressing my problem on Rennlist.I took the motors from their housings, thinking I could substitute other 12 volt motors, but part of the housing is molded into the motor."
Yeah, the A/C condensor and evaporator motors and the fresh air motor are the same way.
"I might cut the shaft and remove the squirrel cage for more free flowing air."
I think like you can just pull the squirrel cage off the shaft.
"Please inform me as to which Grainger motor you used for the engine blower."
It's not too hard to do if you're a little bit handy. The Grainger motor is not a direct bolt-in, but it's still pretty simple.
The Graniger motor is number 2M197 - you can order it on their website for $22.73.
You need to pull the fan motor and housing off the engine, very simple. Remove the old fan motor and squirrel cage. You'll have to fabricate a round plate to mount the Grainger motor to the Porsche housing. I used a piece of .080" aluminum with three holes to mount to the housing, and then a larger center hole and two small mounting holes for the motor.
The Grainger motor has a 1/4" shaft, and the Porsche fan has a 5/16" hole. I found a perfectly sized bronze bushing at a hardware store - 1/4"
id, 5/16" od, 3/4" long, or you can make one from some 5/16" X .028 wall tubing. Then I drilled and tapped the boss on the fan to accept an allen-head set screw (sorry don't remember the size) to hold
the fan on the shaft. The shaft has a flat side, so if you also drill the bushing you can lock it on well. To gain access for the drilling and tapping, I removed one of the blades on the fan, and another on the opposite side to maintain balance. Assemble the motor to the housing, then position the fan correctly before you tighten it down. I also used some Loctite to be sure everything stays together.
The new motor housing is slightly shorter and slightly larger in diameter. It fits in the Porsche mounting cradle fine, but I changed to a
slightly longer bolt for the band clamp that holds it all together. Sorry, don't have any notes about the size - I think it was an 8mm metric, not sure about the length.
I snipped the wiring harness off the old motor and spliced it onto the wires from the new motor (black is ground on the motor, brown is ground
on the plug), so it plugs in like stock.
The whole job took about an hour and a half, and it would probably take 15 minutes to swap just the motor in the future. The Grainger motor is
made by Dayton and seems to be at least as good as the Porsche part. Working fine so far!
Good luck with it!
Dave
