1988 Porsche 928 S4 DIY ABS LIGHT INQUIRY.. Please Help HD PICS INCLUDED*

[anchovi]

Hi, super noobie here.

My uncle recently bought a 1988 Porsche 928 S4.
It wasn't in the best conditions...definitely a good find though!

He has a couple years of experience in automotive mechanical work but lacks knowledge in uncommon cars.
I've helped him out a bit in replacing a couple parts here and there for this particular car which brings me to the ABS light.

The ABS light is on. My uncle suspects that it has to do with the disconnected wires under the hood.

Below is a a picture i took of the car's under-hood sytem. Labels "A" - "K" are disconnected wires which my uncle believes are part of the vehicle's ABS system. Except for labels "F" and "G".

The following labels are indentical on both sides (LEFT & RIGHT) of the under-hood sytem:
Labels "A" & "K" are a group of 5 wires. Labels "B" & "H" are dual wires wrapped in black plastic. Labels "C" & "I" are also dual wires wrapped in black plastic. Labels "E" & "J" seem to be ground wires.

(Ps. I know very little about automotive technology in general so i ask you guys to please bare with me.)



* Label "A" (closer look below): a group of 5 disconnected wires.



We think that two wires from label "A" are supposed to be connected to label "B" using some kind of connector bridge.
That leaves three wires left. Two of them possibly go connected to label "C."

Label "B" : Two disconnected wires wrapped in black plastic.
Label "C" : Also two disconnected wires wrapped in black plastic.



The last wire from label/group "A" possibly needs to be connected to label "E"

Label "E" (Below): Very certain that this wire is ground.
Label "D": Unknown Male Connector. (Please Help Identify)

* of course...this is a just basic idea. We don't know exactly what wires correspond to each other since they don't seem to be color cordinated
nor do we know if that would even be a solution. (What are your thoughts?)



Label "F" (Below): Unknown Female (?) Connector. (Please Help Identify)



Label "G" (Below): Unknown Wires.

My uncle says the two wires from Label "G" may be for some sensor that's missing since they lead back to the harness. (What are your thoughts?)



Labels "H, I, J & K" (Below): Identical Wires to the ones on the left side.

The basic solution i proposed for the left side, if correct, would apply to the following right-sided wires: (What are your thoughts?)





Input from anyone on this forum that has a bit of knowledge on this subject would be greatly appreciated!!

- Anchovi

[MPDano]

OMG! If I had a 32 V, I could help. Why did the PO cut all those wires? Is this engine a transplant?

[Cam in Aus]

WTF?

My ABS light was on and the fuse kept blowing. I replaced the ABS relay and that solved the problem.

You don't want to test it, but chances are your ABS won't be working. You'll still have brakes, just not anti-lock.

I'm amazed you don't have a bunch of other issues with all those wires cut.

[djantlive]

J is the ground wire for ABS. i can't tell you about the others. there are basically ground wire on each corner for the ABS. they need to be bolted back to the chassis. use some sand paper to make sure there is good contact. that solved my intermitten ABS warning light.

the other wires could be for the cruise control as well as other accessories.

[tisilrad]

i think the plug in at F is the cam position sensor..the whit/brown shelded wire probably feeds it(the wire with the gray sheath...). the engine will run with it disconnected ...but not well. You really need a wiring diagram to repair this...there are a lot of ground wires cut there.

[tisilrad]

connector D is the hood light switch

[tisilrad]

G goes to the cam position sensor plug in at F..you will have to get a new head for it and splice it in...if you have access to a junk yard you can walk through i would suggest you look at wiring harnesses for BMW as these will have to correct connectors that you can cut out and splice into yours. Some VW also have these.

[tisilrad]

E is ground wire for the ABS on the rt side, like J above. The dual wires(i and c) that are brown are ground wires as well but go into the plug from the brakes ...should have a 2 prong weatherpack style plug in ......from the wear sensors. these are not that important. I need to research what the dual red wires are...(at H)

[Ahspros]

Cover came off plug going to control module and now do not know which wire goes where. this is a 1986.5 928s with automatic. Have 9 terminals going to plug. Does any one have a color code for this item?

Walt

[Mrmerlin]

if you get the WSM then you will have elex diagrams,
Roger sells a CD made by Jim Morehouse with lots of extra info

[Sapientoni]

ABS faults. Sometimes there's build up of rotor dust on the abs (magnetic) sensors that triggers that ABS light. when you get the wiring straightened if you still have that, check them.

[Sapientoni]

I have never had good results from any 928 cruise control, '81, 86.5, '87.