Roger's HVAC blower retro kit
#1
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Just a FYI for anyone whose blower is noisy or dead. My 82's blower died a few days ago and after weighing all the options, I bought 928sRus Bosch replacement motor and wiring harness.
The entire procedure took about 3 hours, but that included removing the hood, windshield trim piece and cleaning years of gunk and rust from the various parts removed from the blower assembly.
You don't have to remove the hood and completely remove the trim piece, but it made the work so much easier on my hands.
My old motor had almost seized and Roger's new motor is silky smooth and at least twice as powerful as the OEM unit. Installation of the motor is simple with zero trimming of the plastic. The motor fits like the OEM unit. The wiring harness and instructions were very straightforward and simple to install.
Now my A/C blows like a hurricane on position 4 and no more squeaks from under the dash. If your blower is need of replacement, the $285 for the new unit is well worth it, especially in Houston in summer.
Thanks again Roger!
The entire procedure took about 3 hours, but that included removing the hood, windshield trim piece and cleaning years of gunk and rust from the various parts removed from the blower assembly.
You don't have to remove the hood and completely remove the trim piece, but it made the work so much easier on my hands.
My old motor had almost seized and Roger's new motor is silky smooth and at least twice as powerful as the OEM unit. Installation of the motor is simple with zero trimming of the plastic. The motor fits like the OEM unit. The wiring harness and instructions were very straightforward and simple to install.
Now my A/C blows like a hurricane on position 4 and no more squeaks from under the dash. If your blower is need of replacement, the $285 for the new unit is well worth it, especially in Houston in summer.
Thanks again Roger!
#2
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I appreciate your comment. I've been mulling over the purchase for my own car; the one big difference between us, as you know, is that AC isn't really that important up here at 8300 feet.
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Jim - the motor comes with the wiring kit for $285. Thanks again to Jim and Greg for working out the wiring kit - made by Greg Brown so you know it is perfection personified.
Marty - glad we were able to help you keep cool - thanks for the nice review.
Marty - glad we were able to help you keep cool - thanks for the nice review.
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Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission?
George Layton March 2014
928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."![thumbsup](https://rennlist.com/forums/graemlins/bigok.gif)
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Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission?
![thumbsup](https://rennlist.com/forums/graemlins/bigok.gif)
928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
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I'm getting ready to install Roger's new blower motor but my tech guy says there is no resistor pack located on the side of the blower box on my 1994 GTS as indicated on the instructions to plug the included wiring harness/relay in to.
Are we crazy?
Are we crazy?
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On your '94 this was relocated to the bracket for the wiper motor (far over on the drivers side ) where the intensive washer used to be. Same thing basically - though on a 94 you only have 3 resistors (speed 0 is actually Off) and no thermal device - so you can never have magic blower syndrome in a '94/'95.
You may need to extend Roger's kit wiring for this... I heard the kit includes beefier wiring... what exactly does the relay do here?
Alan
You may need to extend Roger's kit wiring for this... I heard the kit includes beefier wiring... what exactly does the relay do here?
Alan
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Thanks, Alan - very helpful!
I may be mistaken as I have not seen the wirting harness, but my understanding is that due to the higher current draw on the new motor the harness takes 12V off the resistor pack instead of through the control head switch. The fan switch then becomes a voltage trigger via the relay, rather than directing current from it to the blower.
Make sense?
I may be mistaken as I have not seen the wirting harness, but my understanding is that due to the higher current draw on the new motor the harness takes 12V off the resistor pack instead of through the control head switch. The fan switch then becomes a voltage trigger via the relay, rather than directing current from it to the blower.
Make sense?
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The usual blower config is that it is fed by 3 wires:
1) Ground (2.5mm^2) to one side of the motor (grounded at instrument pod ground) This is a bit long
2) DEF (2.0mm^2) to the positive side of the motor (back to DEF relay on on CE)
3) Blower resistor pack feed - indirectly from the blower switch (2.5mm^2) also to the positive side of the motor
On the face of it these are more than adequate for the stock motor (and more) - the DEF wiring is the lowest spec here a simple relay could supplement that...?
It would have a to be much more than just a relay to replace the blower switch/resistor combo.
The configuration on a '94/'95 is the most different of any year - it's still mostly the same but it would be nice to know what is being relied upon here to make sure that it will still work for you.
Alan
1) Ground (2.5mm^2) to one side of the motor (grounded at instrument pod ground) This is a bit long
2) DEF (2.0mm^2) to the positive side of the motor (back to DEF relay on on CE)
3) Blower resistor pack feed - indirectly from the blower switch (2.5mm^2) also to the positive side of the motor
On the face of it these are more than adequate for the stock motor (and more) - the DEF wiring is the lowest spec here a simple relay could supplement that...?
It would have a to be much more than just a relay to replace the blower switch/resistor combo.
The configuration on a '94/'95 is the most different of any year - it's still mostly the same but it would be nice to know what is being relied upon here to make sure that it will still work for you.
Alan
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I was not aware that the resistor pack got moved in 1994. Goody.
Looking at the wiring diagram, it appears that the black wire that comes from the resistance group and goes to the fan motor plug in is still a 2.0 gauge wire. The wire that comes from the defroster relay also still appears to be a 2.0 gauge wire.
So, the problem is still the same as with the earlier vehicles....the 2.0 gauge wire is too small for the increased amperage of the new blower motor and the wire will get overheated/melt.
Randy, you can either take a picture of where your relay is located, along with a picture of where the fan motor plug is (if they changed that, too) and I will make you up another loom with extended wires.....or you can have your mechanic extend the existing wires to reach your fan resistor.
Looking at the wiring diagram, it appears that the black wire that comes from the resistance group and goes to the fan motor plug in is still a 2.0 gauge wire. The wire that comes from the defroster relay also still appears to be a 2.0 gauge wire.
So, the problem is still the same as with the earlier vehicles....the 2.0 gauge wire is too small for the increased amperage of the new blower motor and the wire will get overheated/melt.
Randy, you can either take a picture of where your relay is located, along with a picture of where the fan motor plug is (if they changed that, too) and I will make you up another loom with extended wires.....or you can have your mechanic extend the existing wires to reach your fan resistor.