jns

I can see at least one reason why my car won't start and that would be a broken wire harness for the ref/speed sensor wire. This wire is on the harness/DME side of the wiring so buying another reference sensor won't help. How might I repair this shielded wire inside? Can it be soldered or is it like an oxygen sensor wire where you can't solder it without causing bad readings from the sensor? New harness or section of it to the DME? Thanks for your help! I did a search and saw this topic but there was no solution posted.

IceShark

Just solder it back up, move the shielding over the joint and heat shrink. Glue lined would be best but you probably don't have that so put some silicone electrical caulk on it and then shrink. Heck, even normal silicone calk will work in a pinch.

This is not like the O2 sensor that wants external atmosphere references. Just make sure the shielding is over your completed job as other electrical noise may mess up the signal.

PorscheDoc

If the wires are broke far enough away from the connector then you might be able to splice it. I tried and it didnt work all that well. There are 3 wires, and the shielding is actually one of the wires (ie, it acts as a shield and also it plugs into one of the connector ports at the connector itself. I ended up replacing the wiring harness.

On another note, i just put in a brand new wiring harness into an S the other day......came from germany and they had a hard time finding one.....1000 bucks, but man it almost brought a tear to my eye how soft and flexible it was.

IceShark

The shielding is really a ground conductor? Well, that may cause a problem as it is going to be tough to restablish if it is totally cut through. Soldering, well you will probably melt the underlying insulation. A crimp of some sort is probably the way to go. Or strip the shield back enough to crinp and solder it away from the insulation. Those are some ideas off the top of my head to try and rehab the situation.

It is probably a stainless mesh. That can be real hard to get solder to stick to if dirty, which I'm sure it is.

Tom M'Guinn

If patching doesn't work, it might be easier to get a replacement connector and a few inches of the harness from a junk car, and then try to connect that (and its shielding) to the existing harness. I seem to recall seeing a metalic tape used for splicing shielded wire. Might want to check with an electronics guy/board on that. I could be dreaming again. Also, might as well clean the bellhousing ground while you are in there.

jns

Thanks for the info. I'm not sure how well the connector will work after it's soldered and if I can get that wire mesh back together right. How much of the harness will I need if I want to replace the factory wiring? Is there a section of it or will I have to replace it all? Also, has anyone successfully resoldered the wiring back and has it working right?

z3bra

I had one of the connectors fall apart on mine from age, I just cut it out and spliced in a 3 pin molex connector on each end. The biggest issue in doing so is that there isn't a lot of extra wire to work with (particularly on the harness end) so only cut off as little as absolutely possible. I haven't noticed any problems from using the molex plug. I crimped mine first and then soldered it on the pins. The shielding just seems to be tinned copper so soldering wasn't a problem on that one either. Just make damn good and sure you get the pinouts on each side correct and written down before you cut anything as the colors are completely different on the harness side and the sensor side. If you want some extra wire length, just find some shielded 2 conductor wire somewhere such as an electronics supply place and splice in an extension. Yes you will probably lose a small amount of the shielding function in doing so. Since running mine with a molex plug hasn't created any noticable problems, I doubt splicing in a short extension would either. (Probably not a bad idea to keep it as short as possible just the same).

I think that eagle day place carries the AMP Junior Timer connectors and pins but they're stupid expensive, something like $1.50 for each conductive pin and several dollars for each plastic housing and rubber boot. I can't remember where I found them from an electronics supply house but they were a lot more reasonable there other than minimum order quantities being a factor. (It was somewhere like DigiKey but it wasn't Digikey for what it's worth) Anyway, just get a decent molex pin crimper for 10 bucks and some molex connectors. (either the .062 or the .093 ones will work) If you're worried about watertightness then look into weatherpaks or the like. Honestly based on where the connectors are in the engine compartment, if you're getting much water up there you should probably make sure you didn't accidentally drive into a lake or a swimming pool.

Ski

www.eagleday.com

www.kayjayco.com

z3bra

Thanks Ski.

Any idea if either of those places carry some of the male versions of the connectors they list? Neither of them is the place I found before so I'll keep trying to dig that one up.

Ski

ONe of them does carry the male, pins, and even the correct rubber boot!

z3bra

And now that I think about it, with the exception of the sensors for the reference/timing, all the other spots on the car using those the male portion is part of the sensor itself or in the case of the fuel injectors, the injectors themselves.

I would say that if I was to redo the wiring harness, I think I'd try to make adapters for weatherpaks or something more readily available here in the US. Twenty-five bucks for a 3 contact plastic connector is a bit on the high side. I'd just as soon use metal shell mil-spec cannon plugs if I'm going to pay that much for connectors. It's one thing to be a complete cheapskate like we all do on these cars at times, but there are some cases where the price does not even remotely reflect the actual worth of the part considering what it is. These things are available in the UK for 1/3 to 1/4 the price for instance.

Robbery I tell ya, robbery. Not that the Timer's are a bad design by any means, hell any connector under the hood on our car is going to crap out eventually (except maybe metal cannon plugs which won't crap out for a lot longer period of time). Too bad it complicates things that most of the sensors use the opposite end of the timer connectors. (Coolant temp, the two for the flywheel, fuel injectors, AFM, Knock sensor, seems like a few more too that I'm probably forgetting.)

Ok, done ranting now. I feel better already.

robG

Anyone happen to have the wiring from the reference sensor back to the DME? I could also use the same for the speed sensor.
jns-have you had any luck patching the wiring back together?