martinss

In some diagrams (such as this for an 87 S4) the ground point MPIV is under the hood attached to the wiper mounting plate (and shows a picture of it when you mouseover). I have that in ground in my '88 S4. On the other hand this annotation of the same diagram says it is in the, "Drivers footwell above the parcel tray near the steering column." I can't find one there in my '88.

So is there only one MPIV and it is in a different place in different years, or are there two ground points?

UPDATE:

I found MPIV aka GPIV. It is actually on the steering column support on the left side (for LHD cars). It is unmistakeably a system ground point based on the number of wires coming to it, in contrast to the single ground wire coming to the wiper support frame under the intensive washer bottle (see pic later in this thread).

Here are some pictures. As you'll note I have my dash out, so it made finding the ground point easier. I might never have found it otherwise. References to it being on the firewall near the steering column are misleading - that's where I had been looking. First the general location (red arrow) in a picture taken through the driver's door:



Then somewhat closer:



And finally a closeup:



So mystery solved. Many people have clearly been mislead as I was. The good news is that it is probably the most protect ground point of them all. As you can see, there does not seem to be any corrosion on mine, unlike other points.

It does look like something was spliced to one of the wires on mine tho. I'm in the process of tracing all PO changes.
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Thanks.

White Lightnin'

Martin, IIRC -when I replaced my wiper motor, that ground wire was attached to that motor. Therefore, it would not be a 'system ground'...

[mods may want to combine this with "Cleaning Grounds" thread for simplicity?]

Hilton

From memory you have to remove the intensive washer reservoir to get at it - its on the stand-off frame the wiper motor is on. Actually I didn't bother cleaning that one on my ground cleaning, although I have done so on one of my cars when I had the wiper motor out.

syoo8

AFAIK there is only one ground point and yes, it is near the driver's footwell.

Hilton

There is also one on the underside of the steering column

martinss

Mystery solved - there is only one and it's on the steering column support not the firewall - original post updated. Thanks to all for their input.

Landseer

Great picture. Good work.


Wiper (and coil) "grounds" are for radio noise suppression.

jwbeck17

Thanks for this! I missed this one last cleaning, but got it now.

Speedtoys

it is near the firewall.


As it is not near the tail lights.

jwbeck17

I have an '89, and once you remove the parcel shelf and look on the steering column right behind the bottom edge of the dash trim, you will see it and be able to access it.

gazfish

Looks like wires would spring away in multiple direction and be a pig to put back together in that location.

Alan

The wiper motor grounds via its case - so those pictures that show the wiper motor mount bracket as GP IV (or MP IV) are confusing. The bracket is connected to GP IV so as to firmly ground the wiper motor, but the actual GP IV is in the car as shown by Martin. You could use the wiper bracket as a ground in that area - however it will move around a bit electrically when the wiper motor is on because it will take a fair current on high mode. that won't matter for most things - but it is not an ideal ground for sensitive electronics (e.g. sensors, meters etc).

Alan

jwbeck17

Koenig-Specials 928

Put a tie wrap around them to keep them from escaping

chart928s4

Reviving an old thread (so I can find it again).

Search keywords: 928, ground point IV, GP IV, GPIV, MP IV, MPIV.

The location of this ground point is different on my '91 S4. I suspect airbag cars, i.e. 1990-1995, had it relocated. It is indeed near/on the firewall but not actually that close to the steering column. It is behind the instrument panel and completely inaccessible and invisible with the pod on.