Deranged 1984 Wiring Schematic -

[JK McDonald]

As a precautionary step before finally buttoning up my dash and instrument pod installation I was testing all the fuse panel circuits, relays, headlights, A/C, stereo etc…. what the !!! - no rear running lights, side marker or brake lights. Backed tracked my last few assembly steps – then got serious and broke out the multi-meter. I finally realized that the (black plastic box) bulb testing circuit mounted near the glove box was yet to be plugged in.

Since all of the front end lighting was working – this circuitry must bypass the bulb testing box . I had fully expected the worst and thought I’d find the culprit to be a fused rear wiring circuit, bad relay or a pulled wire somewhere. One question - Why would Dr. Ferry Porsche OK a change from the simplistic and easy to follow wiring schematic format used up to 1983 to the schizophrenically deranged layout of 1984 ? Using the 1983 schematic you can quickly focus in on the problem while the 1984 diagram had me chasing down potential phantom problems for hours because you simply can’t follow the logic. Is there a 1984 schematic available using the 83 and earlier format ? Any help would be much appreciated.

Michael

Now that I've compared the 1983 schematics to the 1984 version - I simply plan to use the 83 diagrams on my car for most applications. This afternoon I spent some serious time on the 1984 diagrams trying to get from each external circuit to the fuse/relay panel connectors and then back out to the final component. This process seems pretty ridiculous unless you have a major atomic meltdown. Thanks for everyone's helpful suggestions - Michael

[Danglerb]

Are you talking about the ladder diagrams vs the wiring diagrams?

My "guess" is that ladder diagrams come from an earlier stage in the manufacturing process, and were replaced with the wiring diagrams once they were ready for production use.

From the CD I would say those are all we get, but other efforts may exist.

I think 83/84 is the transition point from the older ceramic fuse CE panel to the newer blade style, as well as many other electrical changes.

[Alan in AZ]

'85 was the transition to the new CE panel with ATC fuses. '84 started migrating to a wiring diagram format vs the current flow diagrams of the older models.

There are pros & cons to each.

I prefer the wiring diagrams because although harder to read they are actually more complete. The wiring diagrams are functional & physically based but mix many subsystems together.

The Current flow diagrams are more localised to invididual functions and more self contained, easier for dubug.

The Current flow diagrams however show no routing or looming information and connectivity (physical mechanisms) and physical location is really rather poorly defined.

There are no cross-overs between these - no current flow diagrams after '83 and no
grid type wiring diagrams before '84... The 85 and later diagrams started to get cleaned up and spaced out into a larger format which makes them easier on the eyes... you still need to know the decoding tricks (magic decoder ring!). The wiring diagrams are also available in (rare) approx 3 foot by 6 foot sheets - great for my eyes these days! but a bit unwieldy

However most things on an '83 are the same as on an '84...

Only the rear markers, rear/side markers & stop lights are monitored by the bulb control unit, while all 4 turn signals are implicitly monitored by the load dependant flash rate of the stock flasher...


Alan

[Normy]

The problem with the newer wiring diagrams is that there is NO coherent explantion of how they work.

I've been trying to trace-down why my mirrors quit working. I have a good fuse, and I recently changed the left switch for the two mirrors. At the same time, I replaced the right mirror with a part from 928 International.

I still can't get it working, and when I look at that diagram- I can't understand it! I follow Porsche's lines, and they wind up at postion "E22" on the central electric board. Where is this? Is this on plug "E", and is there a labeled position "22" there? The later schematics are definitely more advanced, but Porsche did a ***** job of explaining them to us!

That seems to be the problem: We need a table of contents!

N!

[Alan in AZ]

Normy - well thats almost true... Porsche certainly never published an explaination of the wiring diagrams...

To their defence they didn't make them for DIY owners - they assumed these were only for the internal use of Factory Trained Technicians...

Alan

[Danglerb]

The CE plugs have two rows of 5 contacts, first digit is row, second is the contact number.

I took my Jim Morehouse CD set to Kinko's and had several model years diagrams printed out on the large format printers for less than $20.

[Landseer]

Michael,

I use a combination of 83 and 84 diagrams.

Also, I built an excel spreadsheet out of the two diagrams that tells me what each wire on each CE panel operates. I'd post it up, but can't figure out how to attach it here.

Also, the reading of the diagrams is decrypted in some of the auxillary documents in the CD's that Jim Moorehouse sold me.

[Danglerb]

Maybe post the files on www.Rapidshare.com ?

[Landseer]

So, I tried to follow Mike's approach. Below is the file on rapidshare, which you should be able to download for free.

Its not perfect, some parts are incomplete, but its really been helpful for me.


http://rapidshare.com/files/238483655/Central_Electric_DRAFT_Plug_Map__USA_1984_928_in_e xcel_97-03.xls |

[Alan in AZ]

Well I started a little project years ago and the first part was a wiring diagram primer. Its really oriented around the S4 + models - but applicability back to '84 is pretty good.

You can find it here:

Porsche 928 Wiring Diagram Primer Doc

Alan

[Niles]

Alan - Excellent write - up. It will be very useful to me. Thanks for sharing.

[Alan in AZ]

I just need to finish off the rest of it... 400 pages & counting...

Alan

[NewSharkOwner]

Alan in AZ...Please Help? I am a new owner of a pretty Lady 84 with CE Panel issues. If you have finished the layout and can send it to me I would GREATLY appreciate it. My shark started smoking the other night behind the pod. Took an all nighter to find and correct the issue. Melted wire I was trying to chase down was a wire that was cut in the back of the pod that somehow from the PO was cut and never addressed. If you or anyone else has a layout of the "rear" of the CE Panel that describes in detail where all those SAME COLORED jumper wires belong I would gladly pay you for the information!! For some odd ball reason the PO decided to make some half baked connections using regular electrical connectors instead of the shrink wrap ones and I have NO IDEA what the front panel connections (lower section of the front of the CE Panel) connect up to. I have tried to follow the diagrams but WOW are they a mess. I understand the A-W and the pin outs side 1 side 2, but, trying to diagnose a fuel gauge problem (completed) and many hours trying to figure it out, I realized that a layout of the rear jumpers on the CE Panel would have helped saved me hours of frustration.

My new Lady is a 1984 928S. Bought her with only 66k orig and she flies!! Now to get these electrical issues worked out!

Thanks for any and all your help.

p.s. Tried accessing the rapidshare file listed about and I am getting a 404 error code...is there another place the file can accessed?

[stepson]

New Shark owner,

I think this thread from RL might help:

Updated Single Page Central Electric Panel Relay, Fuse & Plug Details (All Years) - Rennlist Discussion Forums