dougs968

I had posted on"what I did to my 968" last week about my starter issue, but things have gotten worse. From the beginning.

My starter has been showing signs of old age so I replaced it with a used one. The used one stayed engaged even after the key was turned off. Had to disconnect the battery to make it stop. Put my old starter back on. No problems.

Next day, made a couple stops on the way to work, car is running great, starter works fine. I made a hard right turn onto the street that work on and then, HOLY CRAP, WTF IS THAT NOISE!!! Went the last 100 meters to work, turned off the ignition. Fine except the starter is still engaged. So I sprint in and get a 1/2" wrench to disconnect the battery. By the time I get back, (probably 45 seconds) the starter had quit cranking. I disconnected the battery anyway. Sniffed around for that fried electrical smell or fires. None found. A couple hours later hooked up the battery and it started just fine. Repeated two or three more times and drove it thru the parking lot. There it goes again. So it gets parked again.
After work I drive it into the shop. With the starter engaged the whole time of course. After disconnecting the battery again had a couple fairly bright EEs from work have a look. First thoughts are a starter wire has come in contact with something and is causing a short. I loosened and retightened the wires. No change. Checked all the fuses and two relays that had anything to do with the ignition. No change.
At this point they are thinking that the contacts in the starter solenoid may be fused together or there is a problem with the ignition switch.
The next thing they have me do is remove the small red wire that is held on the solenoid with a 10mm nut. The car won't start, as expected. Put the wire back on and it starts, all seemingly back to normal. The engineers are very puzzled. It's like it reset itself. It sure beats the hell out of me.

For future reference, I was able to drive the car the 25 miles home that night. Started the car with the small red wire in contact. Then disconnect the wire and e-tape it out of the way with the car running. Just don't kill the engine till you get where you're goin' or you're screwed.

My new/rebuilt should be here tomorrow. I am pretty sure that the starter didn't do the oil-lite bushing any favors so I ordered one of those too.
I sure hope it is just the starter. One of the engineers is going to make me a simple starter kill switch, just in case.

Any of you guys run into this problem? What are the odds of two starters within 12 hours of each other failing with the same symptom? Anything else I should check?

Thanks guys,
Doug

RajDatta

I have seen a similar problem in a 951 where the starter cables came in contact with teh exhaust and firend themselves on to the exhaust. This caused a similar starter behavior. But as you mentioned, you didn't see any short of any kind.

dougs968

On closer examination this evening, after cleaning all the rest of the accumulated gunk, I think I located the short. The heavy gage cable that also contains the small red wire within a thick sheathing. I noticed some old electrical tape peeking out from the sheathing that was wound around the red wire. When I removed it several fairly large chunks of old black wire insulation fell out. Looking inside the outer sheathing, both wires were showing copper and were in contact with each other. At this point I think the smart thing to do would be replace the cables.
Raj, I think you are on to something. Altho my cables didn't appear to have come in contact with the exhaust, over the years being so close to the exhaust may have caused them to deteriorate from the inside. Could this be possible?
I will probably have one of the electronic tech guys at work make me some new and maybe improved cables. I will take notes of lengths, gages of wire, ring lugs, etc.

The new/re-built in Hungary genuine Bosch starter arrived yesterday. $215 with exchange from my local NAPA. Included was the bronze oilite bushing. I will make the extraction and installation tools tomorrow or this weekend. When I'm done with them they will be available to loan out if anybody needs. Looks like I'll have a spare bushing when it arrives too.

Doug

dougs968

Just removed the bad cable. It split into two other cables. One going to the alternator, the other to a connector next to the firewall behind the brake master cylinder sort of. I presume it goes to the ignition. The insulation on the wires, especially the one that goes to the alternator, has crumbled to pieces the entire length. It will not tolerate any bending without hearing it cracking under the outer sheathing. Kind of reminds me of what the Hall sensor did when I tried to disconnect it.

The positive battery cable "seems" to be ok. I still might as well replace it too. I don't suppose anybody knows where to find a factory type positive battery clamp with the small posts sticking out the sides? I did some research on RL and found that an outfit called Ice Shark used a milspec clamp on their cables. I will go that route if the factory type is unavailable.

Got the oilite bushing extraction device made. It worked great. No stress, no mess. I was surprised at the lack of wear on the inside diameter. Using pin gages, the ID measured .473 inch. The end of the starter shaft that goes in that bushing measures .470 inch. Thats only .0015 per side. I would say thats pretty good considering the abuse it just got.

Doug

notthd

Had a similar degradation on my coupe, posted the lengths etc when I pulled a good one for Raj. They dry rot terrible. The cable from the starter to alt that Ys to the fire wall was so brittle it had shorts too.

I'll try to find the post, cheers, mike.

If you need a starter to test with I have a used spare....

dougs968

Mike, did you make a new wiring harness when yours went bad? Me, one of our engineers at work made one based on the remains I gave him. Electrical stuff is way out of my field. Here's what he made me: one 52" piece of Carolprene 6ga welding cable 600 volt, this is the piece that runs from the starter to the alternator. One piece 51" long of I don't know what, but it is sheathed in fiberglass. It is the smaller wire that runs from the starter to the ignition wire connector. The last wire is 48 1/2" long. It is the small blue wire that goes from the alternator to the ignition wire connector, 600v vw-1 18awg csa tew 105 deg c, etc. The lengths all include the wire lugs. All the connectors were crimped, soldered, and have heat shrink tubing. I haven't located the sheathing that the wires were held in yet. It looks like Porsche used three different sizes. I don't really want to wrap all the wires in electrical tape or use the ribbed black stuff.

Anybody, if any of this stuff seems wrong let me know. I feel lucky that there wasn't a fire when all of this happened.

Mike, thanks for the test starter offer. I've got one. But its nice to know just in case. It would be great to see your post on this issue.

I bet there are a bunch of us that need to replace those wiring harnesses and don't know it yet.

Cheers all,
Doug

RajDatta

Doug, I know I had a wire problem. As time goes on, this will become an issue for a lot of cars.

dougs968

The mystery wire I mentioned in my last post is: 51" of #10 SRML black high temp 200 deg C 600 volt with a fiberglass jacket. The double tinned battery cable ring lugs came in yesterday, so one of our tech guys did my positive battery cable for me. It is red in color and is 82 1/2 inches of 1/0 AWG (UL) MTW/THHW/BC-5W2/AWM 1232/1284/1338 600V 105C OR 10269 1000V VW-1 E116277 CSA TEW OR AWM I A/B 105C 600V FT1 W75 O--LL55996. I know, thats probably too much information, but thats what was printed on the cable jacket. Also, the heat shrink is real thick, heavy duty, with some kind adhesive on the inside that also glues itself to the jacket and the ring lug. I am assured that there is no way this cable will ever corrode. The ground cables will get the similar upgrade when I get to them. I still need to manufacture a couple copper lugs for either side of the positive post battery clamp.

It looks like the positive and negative cables will be a pretty tight fit going through the rubber grommet in the battery box. I have some wire run/ wire pulling slime that should do the trick or maybe Armorall, its pretty slippery too.

When all that is in place, all the cables/wires that had that thick black sheathing from the starter up will be replaced with flame retardant braided expandable sheathing. The near exhaust areas will also get aluminum foil fiberglass sheathing.

This may be a little overkill, but I believe this electrical problem will be fixed for good.

Doug

notthd

Wow Doug, sounds like you went all the way. I am going to make one for the cab but have one spare left so I was procrastinating...

I bumped my old post with part numbers and tip to manual comparisons, they both will work IMHO. Tested the same , different lengths, very minor.

I found them new but were 200 bucks or so.... Who knew, this is why I was considering making one..thanks for the detailed info, Hope all is fixed,

Cheers, mike

dougs968

I got one of our guys at work to make me the ground cables yesterday. The long one is 33 3/4 inches long, while the short one is 10 7/8 inches long. These lengths include the ring lugs. These are black and the #s on the jacket are : E315270 1/0 AWG (UL) MTW OR THHW OR BC-5W2 OR AWM 1232/1284/1338 600V OR 10269 1000V VW-1----240954 CSA TEW 600V OR AWM I A/B 105C 1000V FT-1 W75 0---SAE J1127 TYPE SGT. I probably need to mention that on the battery side of these cables, they will be attached to mil-spec type battery clamps. There are two bolts on each clamp. One of course, clamps to the battery post. The other bolt is what the cables go onto. That bolt is a 3/8-16 thread so the ring lugs need a 3/8 hole to fit.

On removal of the old long ground cable. The end that bolts to the back of the block/ above the bell housing area was not very fun to remove at all. From the drivers side located it from above using a light and inspection mirror. I chose not to remove a bunch of parts to get to the nut which is a13mm. The only tool I had to loosen it with was a crows foot. Saw that the bell housing on that side is open at the top so I covered it up just in case I drop something. Which I did. Only room for two fingers to remove the nut. Got the washer off with one of those telescoping pen sized magnets. Now, the stud that the cable ring lug goes on (and a smaller lug with wire that goes to I don't know where) is 8mm. The hole in the ring lug is 8mm. You have to keep the lug pretty square in relation to the stud or it gets in a bind and gets stuck. I used a machinist scribe with a 90 degree end to get underneath the lug and pull up while wiggling/twisting the cable to finally remove it. Then using some nylon cord and a pair of hemostats, threaded the cord thru the lug and tied it. The rest of the cable was easy. The cord is to help me kind of guide the new cable thru the other wires and stuff.

The ground cable I removed was missing about 3 inches of insulation starting just behind the heat shrink, right next to the engine. Looks like the heat got to it.

Now all I got to do is put it all back on. Starting tonight. I have a feeling my daughter will get recruited to get that nut started back on.

Mike, let us know how yours goes. I'm curious as to the condition of your wires and cables. I hope yours are in better shape than mine.

Later,
Doug

D0N

Drove through deep water the other day in my '92 and the starter began to act up. It would stay engaged after turning off the engine and removing the key. Thought it was the solenoid so I replaced the starter thinking that would fix it. Much to my dismay, the problem continued. Checked on line and found this thread and checked the wire harness. Sure enough the 51-inch long 10-gauge wire from the ignition connection to the solenoid was all dried out with crumbling insulation. I fished in a new 10-guage wire and the problem is (hopefully) resolved.
Regards,
Don

D0N

That was a 92 968 6-speed cab.

dougs968

That is what mine is also. Just noticed, I did that two years ago. Much has changed, but the new battery cables are doing great.

Glad you got yours fixed without too much stress.

firemn131

Thnx Doug. Continuing with the junk yard resurection. We got the cams in last night. I found the insulation on the starter wires completely gone!! Did a search and found this thread to find wire gauges, composition and length. In addition to the terminal sizes.

thnx so much.

john

firemn131

do you know the terminal sizes?