When my ignition switch failed I had the following symptoms. No speedometer, no PRNDL indicator light, a check engine light with 6-7 transmission codes, stuck in 3rd but can manually start moving in 1st or 2nd (cant remember) to get up to speed and then shift to 3rd it would clunk going in as the pressure is set to full in limp mode.
**** i had this intermittently for about year before it became permanent. My Burb has a built stage 3 Heavy Duty tranny that was rebuilt like 16 months prior. I troubleshot on the side of the road, in my drive way, found and fixed lots of small **** while doing so like the grounds, big 3 upgrade with 4guage insulated wire. Nothing changed. I had got some technical manuals and studied the wiring diagrams n ****, followed some troubleshooting flows. **** I traced all the wiring from the ignition switch to the tranny plug on Pin E. It almost always read the same as the battery which I couldn't understand, think I fixed something only to have it happen again a few minutes down the road. I never figured it out while it was intermittently failing and then it became permanent.
While my tranny was out of warranty I used an amazing mom n pop race shop in the business for over 50 years and they stand behind their word. They told me that I could safely drive it to them which was over an hour away and they would go over it and fix the problem.
I must have missed some key information or something while explaining the symptoms and in a future conversation when I said something about the prndl indicator light not working he said on the spot that he could have told me that over the phone. But before that, before he could diagnose the tranny the ****** started working again and everything worked. Eventually the tech turns the key again and it fails..... he gives me a call and tells me it the ignition switch. All the troubleshooting I did, combing over 4l60e tech manuals and schematics, following troubleshooting flows.... somehow I missed anything to do with the ignition switch as the culprit. I felt like a dumb ass.
We agreed that if there was anything wrong with the tranny they would fix it for free, anything else was extra and they started to fix the ignition switch thinking I would sa go for it, probably because I spent some serious coin with the prior but I couldn't afford it and told them to put it all back together.
These are great guys and I appreciate what they did for me but I went into a you pick junkyard and bought 3 ac delco ignition switches complete with lock cylinders and keys for like $35 plus a bunch of other awesome scores.
The first ignition switch worked instantly. Such relief. Iv wanted to replace with a new one but cant bring myself to spend that much on something so damn simple. See I tried to fix the switch, just to see if I could. It's almost impossible, a robot must pit these together LOL.
They fail by carbon build up on the rocker switch contacts. It's just that simple. Rubbing alcohol cleans that **** up but reassembling is impossible LOL.
Troubleshooting this is almost impossible but junkyard switches are cheap and chances are good that they will still work. If this ever happens to me again I will save the headache and swap it out first.
Take care
Al
