1987 928S4 Central Electric Panel Refresh Procedure


This is a very simple, but time-consuming, job.

First, unscrew two thumb screws on the the tool tray in the back hatch.

Stacks Image 1948

Next, remove the wing nut that connects the battery ground-strap to the chassis.

Stacks Image 2652

The '87 has a cargo net. I use it to hold the ground strap away from anything that could ground the electrical system.

Stacks Image 2644

Next, there are two (one on each side) 8mm nuts that hold the parcel tray in the passenger footwell. Remove both.

Stacks Image 2636

The bulb control module is attached to the package tray.

Stacks Image 2628

Better to disconnect it, to have more room. I used a flathead screwdriver and gently pried the female end of the connector from the male end of the module.

Stacks Image 2620

This is the Central Electric (CE) Panel.

Stacks Image 2612

This is the lower wooden cover for the CE panel.

Stacks Image 2604

It has two 10mm nuts. Put them in a safe place, along with the washers, and remove.

Stacks Image 2596

The upper wooden cover for the CE panel swivels. There are two 10 mm bolts (one on the left, one on the right) that need to be removed.

Stacks Image 2658

The top of the CE panel has two Phillips head screws that hold it in place. (Mine was missing one.) Remove the two screws.

Stacks Image 2666

The power to the CE panel is at the top. Remove the translucent plastic cover that protects the positive terminals by pinching them at the sides of the plastic.

Stacks Image 2674

Using a 10mm wrench, unscrew both power wires (in red insulation.)

Stacks Image 2682

After freeing the power wires, I put the 10mm nuts back onto the top of the CE panel, so as not to lose them.

Stacks Image 2690

At the bottom of the CE panel, there is a red tab that is pushed down and pulled out. This frees the colored connectors from the CE panel.

Stacks Image 2548

Gently lift the tab on each connector, then gently pull the connector out. Repeat.

Stacks Image 2540

When you are done, the CE panel looks even more chaotic than before.

Stacks Image 2532

Disconnect the ground wires from the left ground point, above the CE panel. 10mm socket.

Stacks Image 2694

Now you are ready to remove the CE panel from the passenger footwell. I put the CE panel on the kitchen table.

Stacks Image 2524

The back of the CE panel looks like grey spaghetti.

Stacks Image 2516

I removed all of the fuses.

Stacks Image 2508

Stacks Image 2500

Then, I removed all of the relays.

Stacks Image 2492

Taking the CE panel outside, I sprayed a short burst of DeoxIT onto every electrical connection in the CE panel. I waited 10 minutes, and then did it again.

Stacks Image 2484

Next, I diluted one part Stabilant-22

Stacks Image 2698

...with four parts Isopropyl Alcohol...

Stacks Image 2476

And after gently cleaning each surface of every fuse and relay terminal with a dremel wire brush, painted the diluted Stabilant-22 onto each terminal.

Stacks Image 2460

Stacks Image 2452

I also painted each terminal on the CE panel with the diluted Stabilant-22.

Then, I put each fuse and relay back into the CE panel.

Now, time to return the CE panel to the passenger footwell. There are two plastic nubs at the bottom of the CE panel (the one pictured below is between "R" and "S." The nub should sit in an appropriately-sized indentation in which it fits. Make sure it is seated properly.

Stacks Image 2656

The power wires need to be draped over the CE panel before screwing it back in place.

Stacks Image 2436

The ground wires do, as well.

Stacks Image 2428

Secure the power wires onto the top of the CE panel. 10mm.

Stacks Image 2702

Stacks Image 2710

(Also, secure the ground wires to the left ground point- MP V)

Secure the CE panel to the floor with a Phillips screwdriver.

Stacks Image 2412

Restore the translucent positive terminal cover.

Stacks Image 2404

The lower wooden cover goes on, with washers. Two 10mm nuts.

Stacks Image 2714

Stacks Image 2380

The upper wooden cover (the one that swivels) goes back on- two 10 mm bolts.

Stacks Image 2724

Almost done.

Stacks Image 2726

Restore the package tray, secure the two 8mm nuts.

Reattach the bulb control module.

Stacks Image 2348

Reattach the ground strap to the chassis via the wing nut at the back of the trunk, restore the tool tray, and you are good to go.