Climate Control Head Compatibility?
05-27-2018, 07:22 PM
#1
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Climate Control Head Compatibility?
I just obtained a scond climate control head for my 84. My original head has a build date of "4 Mai 1983" and the one I just got has a build date of "22 Mai 1985". The part numbers on the circuit board are identical and the only difference between the two is the size of the relay on the board. My original has a clear relay where you can see the windings and has the name "Gruner" on it while the "new" one is smaller and is in a blue opaque case.
In the opinion of the readers, do I have a 1984 head built in 83 and a 1986 head built in 85? Are they interchangeble?
In the opinion of the readers, do I have a 1984 head built in 83 and a 1986 head built in 85? Are they interchangeble?
05-28-2018, 12:06 PM
#2
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Rebuilt HVAC Head Unit - 80 to 83 928 573 060 05R
Rebuilt HVAC Head Unit - 83.5 to 90 - Centigrade 928 573 060 08R
Rebuilt HVAC Head Unit - 83.5 to 90 928 573 060 09R
Rebuilt HVAC Head Unit - 91 to 95 - Centigrade 928 573 060 10R
Rebuilt HVAC Head Unit - 91 to 95 928 573 060 11R
HVAC Head Unit - 91 to 95 928 573 060 11R
Rebuilt HVAC Head Unit - 83.5 to 90 - Centigrade 928 573 060 08R
Rebuilt HVAC Head Unit - 83.5 to 90 928 573 060 09R
Rebuilt HVAC Head Unit - 91 to 95 - Centigrade 928 573 060 10R
Rebuilt HVAC Head Unit - 91 to 95 928 573 060 11R
HVAC Head Unit - 91 to 95 928 573 060 11R
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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."
Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission?
George Layton March 2014928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
05-28-2018, 05:54 PM
#3
Rennlist Member
Thread Starter
I cleaned, greased, and replaced the light bulb in the head unit and its a match. The fan actually moving faster with the new unit (maybe as a result of cleaning) so that project is complete.
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05-29-2018, 11:13 AM
#4
Electron Wrangler
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I just obtained a scond climate control head for my 84. My original head has a build date of "4 Mai 1983" and the one I just got has a build date of "22 Mai 1985". The part numbers on the circuit board are identical and the only difference between the two is the size of the relay on the board. My original has a clear relay where you can see the windings and has the name "Gruner" on it while the "new" one is smaller and is in a blue opaque case.
In the opinion of the readers, do I have a 1984 head built in 83 and a 1986 head built in 85? Are they interchangeble?
In the opinion of the readers, do I have a 1984 head built in 83 and a 1986 head built in 85? Are they interchangeble?
Alan
05-29-2018, 01:11 PM
#5
Instructor
I did what Blake G. is suggesting below along with Greg's fuse at the freeze switch. Belt and suspenders. It works and was not much trouble. I used an empty space in the CE panel for my extra relay.
Add an inline relay fed off of the jump post instead of the Dwayne upgrade which can put excessive load on the traces.
An external relay fed from the head unit's relay as a trigger takes almost all of the load off of the internal relay and is easier to change when it eventually wears out.
I did this in my 81 and had no trouble with it until my head gaskets went.
Add an inline relay fed off of the jump post instead of the Dwayne upgrade which can put excessive load on the traces.
An external relay fed from the head unit's relay as a trigger takes almost all of the load off of the internal relay and is easier to change when it eventually wears out.
I did this in my 81 and had no trouble with it until my head gaskets went.
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Blake G.
Blake G.
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06-01-2018, 08:55 PM
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On all my rebuilt HVAC control units, I include an extra inline fuse that gets installed at the freeze switch to protect the control unit from severe damage if the resistance on the A/C clutch goes way up or if there is a short circuit to ground on the wires that go up front to the low pressure switch and the idle valve.
The '09 control units all had a relay to both power up the compressor and send power to the control units, itself. One relay with dual functions.
The earlier HVAC control units only had a relay to send power to the control board....the power out to the compressor went through the printed circuit board (and through a wimpy contact on the selection lever), itself! Any short circuit, poor contact on the wiper arm, or bad clutch on the compressor resulted in completely melted printed circuit board......a disaster!
On my rebuilt '05 HVAC units, we have now added a second relay and taken the task of turning on the compressor away from the printed circuit board and the wimpy contacts on the selection lever. This is a huge improvement!
The '09 control units all had a relay to both power up the compressor and send power to the control units, itself. One relay with dual functions.
The earlier HVAC control units only had a relay to send power to the control board....the power out to the compressor went through the printed circuit board (and through a wimpy contact on the selection lever), itself! Any short circuit, poor contact on the wiper arm, or bad clutch on the compressor resulted in completely melted printed circuit board......a disaster!
On my rebuilt '05 HVAC units, we have now added a second relay and taken the task of turning on the compressor away from the printed circuit board and the wimpy contacts on the selection lever. This is a huge improvement!
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greg brown
714 879 9072
GregBBRD@aol.com
Semi-retired, as of Feb 1, 2023.
The days of free technical advice are over.
Free consultations will no longer be available.
Will still be in the shop, isolated and exclusively working on project cars, developmental work and products, engines and transmissions.
Have fun with your 928's people!
greg brown
714 879 9072
GregBBRD@aol.com
Semi-retired, as of Feb 1, 2023.
The days of free technical advice are over.
Free consultations will no longer be available.
Will still be in the shop, isolated and exclusively working on project cars, developmental work and products, engines and transmissions.
Have fun with your 928's people!