Ignition switch dead: how to verify mechanical or electrical failure?

[widebody911]

(I'd accidently posted this as a reply in another thread when I was trying to hunt down the answer in the archives)

I went to start the 911 this eve - nothing. It wouldn't turn over at all, and the speedo would just flick a little when I turned to the start position. I was in a hurry so I took my bus, and pushed the 911 into the (old ) garage when I got home.

My first guess was the starter, but it's farly new. I put the car in the air (side note: when lifting one side of the car, make sure the opposite door is shut, or you risk bending your original Westfalia roof rack and scraping the paint on your door. Ask me how I know) and all of the connections looked fine. I cussed at them a little, and then went to try and start it again. Not only did it not start, but now it won't shut off! I disconnected the battery and came in to write this.

What's a good way to tell if it's the tumbler portion that failed, or the electricals? Any easy way to hot-wire the car?

[fred cook]

When my ignition switch went bad (the mechanical part) the key would not turn all the way over to the start position. It would get to the run position and then "hit the wall". You could remove the electrical part of the switch (two screws on the back of the switch) and try turning that part with a screwdriver. It does sound like the problem is in the elec. part of the switch.

Good Luck!

Fred Cook
'80 911SC coupe

[dickster]

what fred said.

if the tumbler sweeps through its full normal range then i would think it would have to be electrical.

when my ignition went bad i could still turn the key as normal.

[RoninLB]

I flipped a good ignition, elec part, at 100k miles. maybe it's
"as long as your in there"..

I forgot if it's the ignition sw or the headlight sw that has the top itty bitty screw fastner, which is a PIA.. anyhow someone posted that there is a plug in the bulkhead so you can reach the screw with a very long screwdriver from the trunk.

if I had to jump it I'd probably tap a permanent hot at the elec panel in the engine comp and jump it to the switched on/off wire of the CD box. then I'd probably jump the fuel pump sol.. then jump the starter sol.
I never had to do it , so no very hard info...

[ruf-porsche]

A volt / ohm meter should be able to verify if the electrical portion of the switch is malfunctioning.

[widebody911]

I've been driving bugs and buses since I learned to drive, and I've had a lot of experience with "won't turn over" with them. Without even really thinking about it, I check the battery leads, then ground strap, then starter connections. Then I look at the ignition switch. Ignition switches on early VW's are very easy - too easy, in fact - to diagnose.

I think a big clue here is that after a couple more twists of the key during testing, the ignition won't shut off.

Looking in the PP cat, the electrical bit is $41; the mechanical + electrical bit is $300. I'd rather not replace the mechanical bits if I don't have to, which is why I'd really like to figure out what's broken before I tear into it.

Oh, and I have a DE next week, so time is of the essence.

[RoninLB]

Originally posted by widebody911
Oh, and I have a DE next week, so time is of the essence.

I'd buy the elec part then dive in.
the worst that can happen is that you'll be using new elec and a plyers..
Ign elec sw is waiting to be dead meat after 100k.. IMO

[yelcab1]

Take the electric portion off, disassemble it, and see what is wrong.

[Doug Steinel]

My 911 wouldn't stop trying to start...even after I removed the key. Changing the elctrical switch in the ignition did the trick.

[ubiquity0]

I've got an unused mechanical ignition switch/lock if that turns out to be the problem.

[Embs]

Pin 86 of your DME relay should get 12V+ with the key in the on position, if not it's probably the dreaded switch unless by chance you have a wiring issue. Pin 30 is hot all of the itme. It is a bit odd though, my experience is that when the switch itself is going bad, usually you get quite a few "hard to start but still starts" scenarios while playing with the key.

Oh well, if your like me it seems the Porsche and VISA are the best of friends!!!