Porsche Enthusiasts Club Forum

Hi. To keep a long story short my 928 was involved in a small accident which did some light damage to the rear bumper panel. I was unhappy with the repairs as they used a GTS bumper as replacement and rejected the repair. The insurance company paid out and then put the car on auction fully repaired but with a silly reserve. I won every failed auction until they finally dropped the reserve. The problem is that the car sat outside all winter at the auction house unused getting damp and a bit mouldy but nothing that a good clean and dry out won't fix. The 2 issues I have however relate to the instrument cluster and the power steering.

On the instrument cluster the Speedo, revometer, petrol gauge, mileage and the oil pressure gauge are not working and there is an abs and traction warning. The lights and the battery gauge do work. The first port of call I think will be the fuse box. I'll check and clean everything in there. Is there any fuses or relays in particular that I should be looking at? If that doesn't work any ideas where to go next?

Secondly there appears to be no power steering. I know there is a leek so keep a bottle of ATF handy. The ATF was low so I topped it up and that usually sorts the power steering out. This time still no power steering. So again is there anything in the fuse/relay box I should look at or any other ideas?

Cheers
Mike

On my S4 the power steering pump was belt driven off the main crank pulley. Is the belt still on?

I had a very quick look earlier and it looked ok. I haven't checked it with the engine running though but will do tomorrow.

mine was standing for ages....changed the fuses for the illuminating ones off ebay....cured 99% of problems....maybe the pas is airlocked?

Update

I've checked all of the fuses and only one was gone which was the rear window demister. No joy with the dash instruments, still the same issue. I noticed a little bit of damp behind the glass of the dash so obviously some damp in there.

The power steering belt is fine but I checked in the reservoir and it looks like the fluid isn't circulating. Should it not be visibly moving? I'll take the torch along later and double check. I forgot to put my contacts in and the light wasn’t great.

On the upside I cleaned all the mould off the leather and then fed the leather with some leather balm so the inside is looking nice again. I've left a plug in heater running in the boot to dry out the last of the damp.

Ok I'm thinking that I'll take the instrument cluster out and give it a check and clean as per the instructions here

http://forums.rennlist.com/rennforums/9 ... price.html

If I had to replace the cluster would I lose the mileage? It’s a digital dash.

You say you,ve checked all the fuses ?.., what you really need to do is renew every fuse on the fuseboard, and clean all the fuse holders in turn (longish job but very worthwhile ) I used a "dremel" with a fine brass wire wheel. This job alone can restore electrical problems as the 928 is afflicted with them.
Remove the battery earth strap and examine closely, they have a habit of oxidising under the black sheath, if it checks out ok clean the point where the strap attaches to the car body, and basically make sure your battery connections are clean and tight.
earthing problems are a big problem with a lot of these cars, and there are quite a few. I know when I did an R/R of my elecrical system, it was a different car afterwards.

I'll check out the battery earth strap as it took in a bit of water in that area, I'll also check out the battery connections. According to the fuse diagram the fuse for the instruments is also the fuse for the kick down. I know the kick down works because I booted it on Saturday. So this makes me think no problem with the fuse, plus the dash has power.

One question about the battery. I have several wires connected up to the positive terminal. Does anyone know what these are?

Hi Mike

Sorry to hear of so many problems after what must have been trying time with insurers.

You mentioned a previous steering leak - where was this located?

Sounds like car has been in unsympathetic hands for months while it was being auctioned. There is no electrical relationship whatsoever with the power steering. I wonder if it has been driven with fluid very low and getting lower becauseof the leak you know is present. If the level is too low the pump will suffer damage, so perhaps that's the problem?

You will need to source a used but good pump if that's the case.

I'm sure Jason Sloan has one, he's in Edinburgh. Phil (928nut on here) sold it to him as a spare.

@stratfordshark
To be honest it was good fun buying it back at auction etc and I made sure I came out on top over the insurance company. Only downside was that it was stuck outside over winter.

I didn't have the car long enough the first time round to get to the bottom of the leak. I need to get it jacked up and get underneath and find out what is going on. Could be the pump, a fluid line or perhaps the rack that needs replacing. Hopefully that will become clearer when I get a chance to get underneath.

My first priority will be trying to get the dash sorted. I'll start looking at that at the weekend hopefully.

If I do need to replace the pod does anyone know if I will lose my mileage? It is a digital dash so I guess the mileage could be stored in the ECU. I can't seem to find that out on the net.

Mike

The ECU (really 2 ecus as the LH handles injection and EZK ignition, but they live next to each other) is very advanced for its day (similar to system used in contemporary cars) but it's dedicated LH Jetronic unit so I would be amazed if it recorded mileage! It's job is simply to read various sensor inputs and adjust injector pulse widths according to its stored map, with ignition timing handled buthe twin EZK ecu. The digidash will just be fed the speed signal and using that to increment mileage on digidash so I think the mileage display will go with the pod!

Maybe Porsche had a procedure for setting the mileage to original figure if thepod ever had to be replaced (hard to think of circumstances requiring complete replacement), but for obvious reasons they never made the procedure public!

I will scout around for any info and look in my tech service info.

Yup as I thought.

Porsche issued Tech Bulletin 9302, which dealt with how to power up a digidash that had been removed from car to retrieve the mileage and trip display info (for purpose of say accident investigation when the pod could no longer be powered up normally). The bulletin showed which contacts to apply jumper wire to, and power connections.

This implies that the mileage display is "tied" to the pod.

If the car has been left outside, maybe the connections just need some contact cleaner? I wouldn't buy a new pod yet.

Thanks all. A replacement would be the last resort and I intend to clean the connections and re-try. I was just wondering what to expect should a replacement be necessary.