Notices
928 Forum 1978-1995
Sponsored by:
Sponsored by: 928 Specialists

Keyless entry installation

Thread Tools
 
Search this Thread
 
Old Jun 16, 2009 | 01:57 PM
  #31  
Kevin in Atlanta's Avatar
Kevin in Atlanta
Thread Starter
Rennlist Member
20 Year Member
 
Joined: May 2002
Posts: 9,272
Likes: 1,327
From: Roswell, GA
Default Relays wiring per Commando

Here's what the Commando instructions say:



Horn/chirp does sounds off. Off to see if I missed a step somewhere.

Later.
Reply
Old Jun 16, 2009 | 10:21 PM
  #32  
Kevin in Atlanta's Avatar
Kevin in Atlanta
Thread Starter
Rennlist Member
20 Year Member
 
Joined: May 2002
Posts: 9,272
Likes: 1,327
From: Roswell, GA
Default

Got the horn working. Next stop hatch.
Reply
Old Jun 17, 2009 | 09:55 AM
  #33  
Kevin in Atlanta's Avatar
Kevin in Atlanta
Thread Starter
Rennlist Member
20 Year Member
 
Joined: May 2002
Posts: 9,272
Likes: 1,327
From: Roswell, GA
Default Hot Diodes/Recifiers

Diodes/Rectifier are very hot to the touch.

Is this correct?
Reply
Old Jun 22, 2009 | 12:40 PM
  #34  
Kevin in Atlanta's Avatar
Kevin in Atlanta
Thread Starter
Rennlist Member
20 Year Member
 
Joined: May 2002
Posts: 9,272
Likes: 1,327
From: Roswell, GA
Default Update - Hatch Release does not work...

I believe that all the connections are proper. I press the trunk release and get nothing. If I pull the diver side hatch release I can hear the relay click.

I did deviate a little bit from the GTS diagram. I disconnected the wire at the hatch pull and added a female clip to the new wire and connected it to the pull switch. On the other end I ran it to the Hatch Disarm on the Alram. I then connected the KE's Hatch (-) to that wire with a tap con. I also connected the 85 from the Hatch relay to that same wire with another tap con.

Any help would be appreciated.

I will take a lot of pictures once all this works.
Reply
Old Jun 22, 2009 | 02:06 PM
  #35  
Alan's Avatar
Alan
Electron Wrangler
Lifetime Rennlist
Member
20 Year Member
 
Joined: Mar 2002
Posts: 13,660
Likes: 621
From: Phoenix AZ
Default

Understand that their diagram for the hatch release will not work for your 928 - they have no conception of how a 928 is wired and it isn't like any other vehicle.

Your diodes should never get hot - if they do it means you have them connected incorrrectly (probably backwards).

The rear hatch will never work unless you modifiy the stock wiring to create a ground path (somehow) when the doors are closed. I showed an example of how to do that - there are several other possible ways.

If you don't do this your hatch release will only work when a door is open (not just unlocked - actually open) - check and see if this is the case. Obviously this is not very useful...

Alan
Reply
Old Jun 22, 2009 | 02:54 PM
  #36  
Kevin in Atlanta's Avatar
Kevin in Atlanta
Thread Starter
Rennlist Member
20 Year Member
 
Joined: May 2002
Posts: 9,272
Likes: 1,327
From: Roswell, GA
Default

Alan, I used your diagram. The brown/white wire has been cut and grounded to the body, the yellow from the hatch release connects to the other end of the switched ground (brown/white) per your diagram.

The diodes (6a) are as printed with the bar end (-) pointed toward the alarm unit. If they weren't would the turn signal lights blink?
Reply
Old Jun 22, 2009 | 03:21 PM
  #37  
dprantl's Avatar
dprantl
Race Car
 
Joined: Dec 2003
Posts: 4,477
Likes: 5
From: Atlanta, GA
Default

I don't know about the trunk release, but my diodes get hot in the GT and also got hot in my former '86 as well.

Dan
'91 928GT S/C 475hp/460lb.ft
Reply
Old Jun 22, 2009 | 03:47 PM
  #38  
Kevin in Atlanta's Avatar
Kevin in Atlanta
Thread Starter
Rennlist Member
20 Year Member
 
Joined: May 2002
Posts: 9,272
Likes: 1,327
From: Roswell, GA
Default

Thank you, that helps.

Originally Posted by dprantl
I don't know about the trunk release, but my diodes get hot in the GT and also got hot in my former '86 as well.

Dan
'91 928GT S/C 475hp/460lb.ft
Reply
Rennlist Stories

The Best Porsche Posts for Porsche Enthusiasts

story-0

9 Vehicles Porsche Helped Engineer that Aren't Porsches

 Verdad Gallardo
story-1

9 Features and Characteristics That Only Porsche People Understand

 Verdad Gallardo
story-2

I've Written 500 Rennlist Articles: Here's How Porsche Has Changed Along the Way

 Joe Kucinski
story-3

10 Most Unnecessary Porsches Ever Built (And Why We Love Them)

 Verdad Gallardo
story-4

Porsche 911 GT3 S/C vs 718 Spyder RS: 10 Categories, One Winner

 Joe Kucinski
story-5

This Builder Is Turning Heads With Its Slantnose 911 Creation

 Verdad Gallardo
story-6

Porsche 911 GT3 Artisan Edition Pays Homage to Japanese Culture

 Verdad Gallardo
story-7

Porsche Reveals Coupe Variant of the Electric Cayenne With a Fresh Look

 Verdad Gallardo
story-8

10 Porsche Colors That Have More Personality Than Most People

 Verdad Gallardo
story-9

Guntherwerks' Final Speedster Creation Is the Ultimate Porsche Restomod

 Verdad Gallardo
Old Jul 6, 2009 | 03:37 AM
  #39  
Bill Ball's Avatar
Bill Ball
Under the Lift
Lifetime Rennlist
Member
20 Year Member
 
Joined: Mar 2002
Posts: 18,648
Likes: 52
From: Buckeye, AZ
Default

I had another idea for how to wire the keyless remote hatch release. Should retain all stock functionality of the hatch release pulls (only work with door open). Also, in cars with dual hatch pulls (i.e., pre-GTS) you would not need any wires running across the car from one pull to the other and would only have to interface the keyless system with one of the pulls. The hatch pulls otherwise stay wired as stock. Alternatively, you can interface with the yellow wire at S11 on the CE panel on GTS's or connector T19 near the CE panel on most earlier cars and leave the pulls alone. The diodes in the hatch release circuit isolate the keyless ground from the door pin switched ground.

Alan, tell me why this won't work. Note to everyone else - this drawing is hacked from Alan's original work.

[EDIT: SEE CORRECTED VERSIONS IN POST #46 BELOW. Note Alan's comment that a relay or transistor is needed on the output from the remote hatch release sionce it is not rated for more than 200-300ma in most keyless entry systems.]
Attached Images
File Type: jpg
keylesswithhatch.JPG (99.2 KB, 278 views)
Reply
Old Jul 6, 2009 | 01:33 PM
  #40  
Alan's Avatar
Alan
Electron Wrangler
Lifetime Rennlist
Member
20 Year Member
 
Joined: Mar 2002
Posts: 13,660
Likes: 621
From: Phoenix AZ
Default

Bill - Conceptually this should work well. I like your idea - the only thing not to like is the installation of the 2 diodes in the tool panel/hatch release area (just in terms of making it tidy and robust), and of course while a single wire must still be wired forward to the controller - it does cut down on wiring across the car for a dual release model.

However I'm not sure that typical KE units can sink enough current on the Aux/Hatch output to support the relay coil current and the motor current concurrently. The motor is a very light duty item (<<1A) but still may be too much for some units... see what the current drive specs are on this output?

Another possibility would be to replace the diode for this with a transistor 9at the rear hatch motor) to provide some current amplification to alleviate this issue - not much more complicated...? Of course another relay is also an option...

You also could just try this out - but I'd check the specs and the motor current when operating first - if you overload this output it may work initially - but create a long term reliablity issue.

For me the wiring wasn't a very big deal - I already have lots of extra wiring bundles to various places in the car so was able to use these.

Alan
Reply
Old Jul 6, 2009 | 01:38 PM
  #41  
Alan's Avatar
Alan
Electron Wrangler
Lifetime Rennlist
Member
20 Year Member
 
Joined: Mar 2002
Posts: 13,660
Likes: 621
From: Phoenix AZ
Default

OK I guess the turn signal confirmation diodes may get hot when operating (lock/unlock etc repeatedly) depending on their size. Mine are very big and probably wouldn't be noticeably hot unless I continued activation for a while (never tried itz) - just due to their themal inertia. Smaller diodes will have less thermal inertia and a higher on resistance so will heat up more and faster (mine are ~40A stud mount diodes).

Alan
Reply
Old Jul 6, 2009 | 02:18 PM
  #42  
Bill Ball's Avatar
Bill Ball
Under the Lift
Lifetime Rennlist
Member
20 Year Member
 
Joined: Mar 2002
Posts: 18,648
Likes: 52
From: Buckeye, AZ
Default

Originally Posted by Alan
However I'm not sure that typical KE units can sink enough current on the Aux/Hatch output to support the relay coil current and the motor current concurrently. The motor is a very light duty item (<<1A) but still may be too much for some units... see what the current drive specs are on this output?

Another possibility would be to replace the diode for this with a transistor 9at the rear hatch motor) to provide some current amplification to alleviate this issue - not much more complicated...? Of course another relay is also an option...

You also could just try this out - but I'd check the specs and the motor current when operating first - if you overload this output it may work initially - but create a long term reliablity issue.
Alan
Alan: I'm using an old Audiovox APS-45, and your warning is appropriate - the channel 2 negative output I would use is rated at only 300ma, and they caution against using it to directly drive anything but a relay - I missed that! I'll revise the schematic. THANKS!!
Reply
Old Jul 6, 2009 | 02:41 PM
  #43  
Alan's Avatar
Alan
Electron Wrangler
Lifetime Rennlist
Member
20 Year Member
 
Joined: Mar 2002
Posts: 13,660
Likes: 621
From: Phoenix AZ
Default

Bill maybe like this:

Alan
Attached Images
File Type: jpg
Slide2.JPG (105.9 KB, 247 views)

Last edited by Alan; Jul 6, 2009 at 05:51 PM.
Reply
Old Jul 6, 2009 | 05:03 PM
  #44  
Bill Ball's Avatar
Bill Ball
Under the Lift
Lifetime Rennlist
Member
20 Year Member
 
Joined: Mar 2002
Posts: 18,648
Likes: 52
From: Buckeye, AZ
Default

Alan:

WOW! That is great. What value do you think Rx should be? Can you give me a common transistor part number I might pick up at Fry's?

Hey, one other thing... I did not use a horn relay but hooked the remote's horn ground output to the wire that goes to pin 85 on the horn relay, which is a BR/WT wire at H22 on the CE panel in my 89. It would be N15 in your GTS. Seems to have worked fine for year. So, I could get this down to one relay.
Reply
Old Jul 6, 2009 | 06:05 PM
  #45  
Alan's Avatar
Alan
Electron Wrangler
Lifetime Rennlist
Member
20 Year Member
 
Joined: Mar 2002
Posts: 13,660
Likes: 621
From: Phoenix AZ
Default

Bill - I updated the diagram - I had missed off 1 extra diode that is required.

The base resistor can be approx 600-1K ohms and you need a transistor rated for approx 1A min continuous. I'd plan to mount the transistor and diode in a little project box on a PCB - so a TO-220 style transistor would be easy to mount and comes in appropriate ranges. You need a silicon NPN with a gain of at least 40 - I don't know what Frys carries but you should find some like this easily enough. the TIP47 - TIP50 series by motorola should work fine.

Alan
Reply



All times are GMT -3. The time now is 01:31 AM.

story-0
9 Vehicles Porsche Helped Engineer that Aren't Porsches

Slideshow: Long before engineering consulting became trendy, Porsche was quietly helping other automakers build everything from supercars to economy hatchbacks.

By Verdad Gallardo | 2026-05-15 12:44:44


VIEW MORE
story-1
9 Features and Characteristics That Only Porsche People Understand

Slideshow: Some brands build cars. Porsche builds traditions, obsessions, and a few habits that stopped making sense decades ago but somehow became part of the charm.

By Verdad Gallardo | 2026-05-13 18:46:13


VIEW MORE
story-2
I've Written 500 Rennlist Articles: Here's How Porsche Has Changed Along the Way

Slideshow: Six years and 500 Rennlist articles later, these are the biggest changes at Porsche.

By Joe Kucinski | 2026-05-11 09:52:55


VIEW MORE
story-3
10 Most Unnecessary Porsches Ever Built (And Why We Love Them)

Slideshow: Some Porsches exist for very specific reasons-others feel like they were built just to see if anyone would notice.

By Verdad Gallardo | 2026-05-06 18:00:32


VIEW MORE
story-4
Porsche 911 GT3 S/C vs 718 Spyder RS: 10 Categories, One Winner

Slideshow: Choosing between the 911 GT3 S/C and 718 Spyder RS in 10 key categories to determine one surprising winner.

By Joe Kucinski | 2026-05-05 12:51:46


VIEW MORE
story-5
This Builder Is Turning Heads With Its Slantnose 911 Creation

Slideshow: A small Polish tuner has reimagined the Porsche 911 Slantnose for the modern era, blending 1980s nostalgia with widebody tuning culture and serious performance upgrades.

By Verdad Gallardo | 2026-05-01 10:49:43


VIEW MORE
story-6
Porsche 911 GT3 Artisan Edition Pays Homage to Japanese Culture

Slideshow: Porsche has created a Japan-only 911 GT3 Artisan Edition that blends track-ready hardware with design cues inspired by traditional Japanese craftsmanship.

By Verdad Gallardo | 2026-04-28 19:37:40


VIEW MORE
story-7
Porsche Reveals Coupe Variant of the Electric Cayenne With a Fresh Look

Slideshow: Porsche's latest electric Cayenne Coupe blends dramatic styling with supercar acceleration, turning the brand's midsize SUV into a 1,139-horsepower flagship.

By Verdad Gallardo | 2026-04-27 19:39:30


VIEW MORE
story-8
10 Porsche Colors That Have More Personality Than Most People

Slideshow: Porsche's wildest paint colors aren't just shades-they're full-blown personalities on four wheels.

By Verdad Gallardo | 2026-04-27 19:38:13


VIEW MORE
story-9
Guntherwerks' Final Speedster Creation Is the Ultimate Porsche Restomod

Slideshow: The last of the Speedsters doesn't just close a chapter, it makes quite the bold, air-cooled statement.

By Verdad Gallardo | 2026-04-22 17:55:04


VIEW MORE