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WARNING !!!!! PAS Pump Power Assisted Steering switch..LOOM RISK

robwright

New member
What PAS switch. There isn't one. The only three cables on the bottom in the area you suggest are the oil pressure sender and switch (2 off) and one cable to the oil level sender. They are in the DME loom but go to the binnacle.
 
Mine has it, it appears only on S and S2 models, I came across the cable which had no connector it just the rubber boot and cables, the switch is on the PAS pump. Reconnecting it caused a short ! and a burnt loom
 
I believe this is an issue in the S models, not sure about others. It's possible it was a recall, but when I did some digging I wasn't 100%. Best to disconnect and tape up, even better to fully remove from source. It was only used for boosting rpm to aid pas pump, but fine without it.
 
Sorry to hear of your woes John...I have replaced most of my engine bay loom using Lindsey harnesses which come with very good instructions...I had a look at their website but couldn't find a replacement harness section for this part on your car. It may be worth asking them though as they do just about everything else. You could always just replace the damaged wires for yourself, you may find some help on the Lindsey site in identifying the different wires that go to the DME as they give detailed step by step instructions for their harnesses. I'm sure that by studying these and using the workshop manuals detailing the DME you should be able to run new wires. You need to find out why it shorted first though, is it possible that these wires were left disconnected for a reason by a previous owner? a little investigation is needed i think...:) this link may help you find your way...open each item and take a look at the 'tech garage' section that gives step by step instructions for each harness http://www.lindseyracing.com/LR/Parts/HARNESS.html hope this helps Pete
 
Well to say fed up is a understatement...its a real P"sser pardon my french !

I was in the process of resolving a Oil Cooler oil leak getting organised ordered parts sourced the align tool (Thanks to Alsdair), cleaning down the oil soaked area ready for the job, thought nothing of it so next day started her up in a short period of time had erratic oil pressure and battery volts too. Here I genuinely thought it was caused by the area I hand be exploring the day before but the damage had been done.

The loom (the American forum suggests its called the DME loom) carries the cables from the bottom end of engine (Oil cooler location) for oil Switch and PAS switch and also low oil level switch up to the front of engine and then joins the injector loom underneath the inlet manifold runs over top of engine block then to bulk head I assume possibly to the connector (14) on bulk head battery side.

I have to say I feel like a right knob looking at the burnt cable damage now, Has anyone else had the similar unfortunate experience and more importantly replaced the loom...so any advice given would be well received now as I look to resolve it myself.

Yes the car runs still but is layed up with battery disconnected !!![:mad:][:mad:][:mad:][:mad:][:mad:][:mad:][:eek:][:eek:][:eek:][:eek:]

This is Heath issue to said S and S2 owners and will KILL YOUR CAR if the PAS switch cables short out or I think in my case cables get reversed !!!
 
looking from the back of PAS pump, switch is top right
23566503B85348B4807D0D11420AEC91.jpg
 
Here's a link to a thread I made about the same subject when I had my S: http://www.tipec.net/_forums/viewtopic.php?f=25&t=16817 Hopefully if you disconnect the pas switch again you might be lucky and the only damage is too these cables, probably best to unwrap the loom and have a proper look.
 
OK I get it now. Wasn't aware it was an S. As already said best to remove I think if it wasn't causing you any particular issue.
 
Thanks PSH and Hallsy, The picture shows the switch and burnt cables, PSH thanks for the info, the cables are fried in the loom that runs below fuel rail i.e beneath the inlet manifold here the loom clipped with cable clamps so easily not got at, so trying to pull a new cable or loom will not pulled through these cable clips/clamps PSH......did you remove the manifolds to get your new loom in ? Thanks John
 
To late for me Rob, wished I know before all this.... the switch has same size 2 x spades on it, with this I thought it was an isolated switch, looks like its voltage critical and I reversed the polarity and so put the volts down to earth....hence my problem now. Its a easy mistake reconnecting a previous make good being aware why it was done in the first place!
 
Having done an engine out and rebuild like Pete you may find it easier yes to remove the inlet manifold. it will give you a lot better access. I lost my oil level light after engine refit. I say lost the failure mode is to be permanently on. I have ended up having to rewire from source straight to the dashboard pinnacle.
 
ORIGINAL: jellytott Thanks PSH and Hallsy, The picture shows the switch and burnt cables, PSH thanks for the info, the cables are fried in the loom that below fuel rail beneath the inlet manifold the loom clipped with cable clamps so easily not pulled through did you remove the manifolds to get your new loom in ? Thanks John
Yes John......manifold was off and all wires that Lindsey did a harness for were replaced, other single wires have also been changed since, still have a few to do such as fueling wires (will probably scrap the DME relay) and lighting. These cars are now getting on a bit, all the wires will have resistance, some more than others...I guarantee that all the wires between engine and manifold are toast and need changing, same goes for all hoses and vac lines... the car will run much better in doing so. Pete
 
Hallsy link is interesting.....possible re-calls etc as known problem. link again below for ref. http://www.tipec.net/_forums/viewtopic.php?f=25&t=16817 Pete why did you go for Lindsey harness is it a straight swap out, looks like I'll need the loom that runs along the top of the engine which has injector cables and connectors for each injector joining affected burnt out Oil/PAS/oil sender cabling. Its a good point about "cable life" because its in a bloody hot and hostile location. Can you recall if the loom connects into the multi way connector on the bulk head supplied by Lindsey? Looks like either way the manifolds have got to come of to case back and at the same time replace the vacuum hoses, I hate this sort of invasive surgery I hope I don't cause more problems resolving it. I haven't even got the oil cooler leak which started all this and prompted all this in the first place its a real p*sser as you say !
 
Rob and Pete I'll die if I had to do a engine re-build like you two...from me I'll take my hat off to you two! Rob...you mentioned loss of failure mode...whats that ?? Pete, I looked at Lindsey thanks for checking and your right mainly 944 8v and Turbo. Either way looks like manifold off to chase the loom and damage, possible could replace burnt out cables (mines a low mileage 55k) but I feel its better to fit a new loom perhaps from OPC fitment.
 
Yes - I wasn't sure about mine, but it did look different to the norm so I assumed it had been updated. You would assume the failure is down to the cables degrading due to oil & heat, then shorting out, which on an unfused circuit would mean melt down of the insulation. Thing is, most pressure switches are just switching a positive, so shorting out the cables would cause no issue (no different to the switch closing) - but maybe as you say, this switch is different, I'd have to look at the drawings to be sure. Either that or the switch or wiring shorts to earth, which would give an issue. For now I would strip back the loom tape and have a look at the damage, you might only need to replace a few cores rather than the complete part of that loom. Removing the inlet on an S isn't too much of a job from what I remember, and will give you more access. Plus, while you have that off you can clean out the oil residue, double check throttle plate & switch are set correctly, check the AOS deals, check vacuum tubing, etc. Hope you get it sorted :)
 
Plus, while you have that off you can clean out the oil residue, double check throttle plate & switch are set correctly, check the AOS deals, check vacuum tubing, etc.
Hallsy, sorry understand the vacuum tubes...what the AOS seals and what about setting up the plate?? could you explain if possible
 
Of course :) When I had my S it suffered from an occasional stall or uneven idle, so to try to sort this I removed the inlet manifold and checked a load of stuff. The inlet was quite oily, as was the throttle body. My throttle body deadstop was set incorrectly so I adjusted this, and adjusted the idle switch to suit. The aos is the air to oil separator, this is the part that is your oil filler. The deals for this can leak and cause some mayo type build up due to mosgure in the oil. I cleaned my aos out and replaced the seals. I also replaced any iffy looking vac connections, pressure tested the j tube and checked that the afm was working ok. After I had done all of the above I had a much improved idle and the stalling issue was gone. I have a write up somewhere, I will find it!
 
Here you go, a few posts down you will see one from me that might help. I also forgot, worth cleaning the isv of you have the inlet off. http://forums.tipec.net/viewtopic.php?f=25&t=13151&hilit=inlet&start=1080#p121301
 
For the attention of Paul Mc just a thought. I don't know if it would be worth making the PAS switch a sticky in Technical FAQ's as an important advisory on 944S and possibly S2's vehicles???. I fell in big time, reconnecting the 2 cables on the PAS pump switch either way they came off of actually cut on purpose. So being new to the 944 scene I've replaced and removed from my 944S countless I.C.E (in car cables) add assorted cables over the years and then add numerous scotch blocks and terminal blocks just hanging off other cables, so with this the risk I would set fire to the car was high... I didn't.....but these two cables have shorted out and fried the DME loom ! If I would have been aware they've been disconnected for a reason I'll left well alone or for members checking to see if they have a risk being connected in the first place....they could make the call to snip and insulate, rather than having them connected waiting to short out! http://www.tipec.net/_forums/viewtopic.php?f=25&t=16817
 

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