Sxrxrnr

For some reason my 59 had a later model ignition switch and lock instead of the correct one. Looks like switch and lock may be from a C2, or a 68.

So I purchased a new switch and lock and just now installed. Everything works well until I turn the key off. I then hear this clash/grind momentarily as soon as the key hits the off position.

It obviously is the starter gear engaging the flywheel ring gear. Only occurs for a moment, but is not good.

No indication that the starter gear is engaged with flywheel while engine is running,,anyway cannot hear anything unusual.

Any ideas besides a faulty switch? I believe all is wired correctly, but with Ron Francis wiring and wiring color coding completely different than GM standards, I may have made an error,,,but don't believe so. I moved wires from like to like on old switch (C2) to new (59) switch. And as noted everything else appears normal. Switch is USA made.

I've not gone any further in troubleshooting but am about too go back out and check further to see what I can find.

Frankie the Fink

Definitely not good. Sounds like your 'start' circuit is being temporarily engaged while the 'run' circuit is transitioning to the 'off' position....resulting in a clash. Sounds like miswiring to the switch, wrong switch or faulty contacts inside the switch.

Sxrxrnr

Have let it sit for a few hours and had a flash and just went out to try it to see what would happen.

What I did was just hit the "start" position for a very brief moment, just enough to engage starter and turn over engine. And before engine could start, I release the key back to the straight "on" position. Then I did this and rapidly went to the off position. Did this to find if the starter would attempt to re-engage when switch was quickly moved from start position to off position. Starter does not either appear to remain engaged when going from start to off, nor does it appear to attempt re-engage when going from start to off.

Right now I'm a bit stumped and this Ron Francis wiring system with their completely alien to GM standard color codes is not helping. I've got the Dr. Rebuild schematic (excellent if you have GM wiring) and the far lesser quality Ron Francis schematic. All appears OK as far as wiring is concerned, so perhaps it is the new switch, but I'm not ready to accept that yet. Tomorrow I will see if I can get another switch.

If all else fails, in goes the original switch until I figure this out. This is a new one on me.

Frankie the Fink

I'm betting you have discovered why you have a C2 switch in the car

rich5962

Wow, I thought when I saw the EXACT same problem on a 64 recently it was one in a million!!! Going from run to off, the starter would kick in. Very strange. Now you have the SAME issue!

In your case, I really would think it's the switch because that's the last thing you changed. However, here is what happened in my case.

The 64 has all of it's original GM wiring, etc. First suspect was the switch, changed that....same problem.

Digging in with a ohm meter checking continuity and suspect shorts, I discovered we had a low grade short between the +12v feed to the fuse box, to the brown accessory feed. I traced it by starting to disconnect things to see if the short disappeared. No luck.

I removed the fuse block, and behind it I found the red #12 +12v feed terminal, and the fused brown accessory feed wire just slightly rubbing against the terminal enough to barely break the insulation. A low grade short. There was no short between the starter circuit to anything. Somehow this accessory short caused some kind of feedback into the starter solenoid circuit. After insulating and moving the brown wire away from the feed terminal, problem gone. I can't explain why this could have possibly affected the starter circuit, other than possibly feeding back through the ignition switch. Very strange.

Rich

L78racer

i had this same problem on my '57 a while ago. look at the accessory connections at the fuse block.(batt+, heater, radio) mine turned out to be one of those was in the wrong place causing inter-action when shutting off the ignition. it didn't make sense as to why but that indeed was the culprit.

Sxrxrnr

I had wondered and considered this in a previous posting a couple of months ago. Why would someone take the stock switch out and replace with a later one! Now with your suggestion and the prior 2 postings, I'm suspecting that someone rather than fixing the real problem, accidentally found that this later switch solved the problem (possibly had one just lying around and suspecting a bad switch, tried it and all was well, and moved on).

Somewhat as a couple of other electrical problems that I spent hours de-bugging in previous threads.

1. Dash TS indicator lights illuminating when stepping on brake pedal.

2. Hit dimmer switch to go to bright lights and dash "bright light" indicator goes out. Hit dimmer to go to "dim" and same light illuminates.

Who are these guys who leave this stuff behind? I know that the owner that I bought this car from had paid someone else likely very good bucks to have this done correctly. This all is another excellent reason to remain with stock GM wiring harnesses when building your car if you can. The color coding of all wiring then at least meets what is illustrated in Dr. Rebuild's schematics, making troubleshooting far simpler.

Now the question might be, what is different internally in the stock switch than in the switch that works ok. I've never seen a "bad" switch do something like this, so I suspect that I too have an electrical gremlin just as with the posting just ahead of this one. This could prove a tough one. The TS light problem likely cost me some 15 or more hours before I resolved. Don't know if I am ready for another marathon, upside down under my dash.

Yea, I'll probably do it! To answer the question on another recent thread, this is why we work on our cars.

Any other ideas out there?

Sxrxrnr

As Alice in Wonderland reported, "Things are getting stranger and stranger",,,or some such.

I had left the situation today to attend a baby shower at a local restaurant,,yea I know, but is for my son's first baby and my wife suggested that my car could wait,,and as I was about to spring for new tires I thought that listening to her was the better part of valor,,so to the baby shower I went. It actually was a lot of fun and my son's wife has a lot of cute young friends that it turns out like appreciate old Corvettes.

But as I'm there, I'm still puzzling over my problem and thinking of what both Rich5962 and IS6racer had found when the faced the same problem and both reported wiring problems at the fuse panel and fixing these, resolved the problem.

So then it hit me, why not disconnect the brown (Ron Francis wiring you know) accessory wire from the switch to see what might happen and at least give me a leg up on where I should begin my troubleshooting journey.

On the way home late this afternoon, I stopped at Corvette Clinic (my local drug of choice purveyor) and told Matt that I may have a problem with the new switch he had sold me and asked him if he'd ever had a problem with any in the past. He said that never had, but volunteered to loan me a switch to try another one.

So now I'm home and the first thing I do is pull the brown accessory wire and fired the engine (not certain if the whole car will be going up in a blast of flames or not) and then turned the switch to "off". The engine stopped and NO grinding noise from the starter engaging the flywheel.

I said great, now we're on to something, but now I've got to find what's causing the problem because now I've no accessories when in the accessory position on the switch . I try them all,,,,radio, horn, lights, heater, turn signals,,,,,they all work perfectly in the run position as they should. But of course nothing when the switch is in the accessory position.

So now what. My guess is that for some reason there is a momentary current flow upon shutdown from the brown accessory wire from the fuse panel and disconnecting it from the switch does not allow this surge to cross feed within the switch to the starter (solenoid) position causing the starter to engage. For some design reason, the C2 switch does not allow this to occur, whereas the C1 switch permits this. So disconnecting the accessory wire resolves this as this surge cannot occur.

1. But what causes this surge from the accessory wire that runs from the fuse panel and where does it come from. Perhaps I too have a short in my panel as others have discovered in theirs. However when I meter this wire to ground there is never been a sign of current. I plan to later to have a meter on this wire at shutdown (pull the wire while the engine is running and stick a probe into it) and see if I get a surge at shutdown.

2. How are the switches different internally. I will meter them tomorrow and try to figure this out, hopefully without opening them up.

3. The suggestion that the C2 switch was installed resolve this problem is likely spot on, but this seems to be a "Bubba fix" instead of figuring out why this Ron Francis wired system fails when the stock GM system would not (the system for which the C1 switch was designed. And who ever decided that a C2 switch was the solution, likely knows something about these switches and the situation that yet I do not.

4. I was thinking on my own "Bubba fix" to place a one way diode in the accessory wire to the switch. This would likely preclude this "surge" to reach the switch at shutdown thereby solving the problem. I don't think that I will do that. Another solution of course would be to place a toggle switch in the accessory wire to use when I would want to listen to the radio when the switch is in the accessory position. Now that would be gold plated "Bubba".

5. I plan to call Ron Francis wiring Monday to find if this is a known problem. The only thing that I believe is really different between my wiring and stock wiring should be the single wire alternator verses the generator, and the electronic MSD ignition system, and hazard flashers. None of which should cause such a problem.

6. One other oddity that I've noted but have not quite pursued to its end. I've been disconnecting the battery ground cable when pulling the switch and have done so several times. Normally I should get no spark at the battery post when reconnecting it. However I am finding that when now reconnect the battery with this C1 switch in place, that I will at times get a spark when re-connecting the ground cable. Have not really checked out enough to find exactly when I will get the spark and when I will not.
I will only get it once,,,if I touch the battery post a 2nd time with the cable, there will be no spark. Its as if a capacitor is holding a small charge and it is being discharged upon initial contact of the cable to the post. This I suspect is related to the momentary surge that causes the starter to temporarily engage upon shutdown.

I knew that I should have paid more to watts, ohms, volts and amps when I was in high school shop.

Sorry for the long odyssey, but this one has me really scratching my head.

Oh yea, the loaner C1 switch has the same problem.

Sxrxrnr

Called Ron Francis Wiring today. They have not a clue as to the problem.

Spent 3 hours this afternoon metering switches and wires. Finally believe that we have figured out the problem. After a trip to the local Radio Shack or Fry's Electronics I will have the diode that I need to fix it. Remember earlier that I had thought of a "Bubba Fix" solution. As it turns out this, if this works it will still be a diode, but not considered a "Bubba Fix".

If our theory is correct, anyone who replaces a generator with an alternator on these C1's should have exactly the same problem and have likely been forced to replace their stock ignition switch with a later model switch in order not to have the starter engage at engine shutdown time.

Another little question. My friend and I discussed if the C1 Corvette ignition switch when in the off position, that it also serves as an accessory position so that one can run the radio with the engine off and not be forced to leave the switch in the run (or on) position which would serve to run the battery down more rapidly and burn your points.

He says that off will not feed accessories and as I remember from the old days, that off was accessory on Chevy's. Too long ago for me to remember, but seem inconceivable to me that Chevy would force you to leave the switch in the on position while parked with your girl friend listening to the radio. If no accessory I guess that you could wire the radio so that you had to turn it off in addition to turning the engine off.

I'll post later what we found and the solution if it turns out that our findings are correct. It is has been a very interesting puzzle.

Frankie the Fink

Errr...its "curiouser and curiouser" I believe...

rich5962

Hmmmmm, this sounds familiar too. Obviously there is current being drawn somewhere. If the doors are closed when you reconnect(i.e. no courtesy light on), then something is on. I didn't realize before that you have a alternator.

I see yours is a 1-wire with internal regulation, and not an identical setup, but when we got our 63 a few years ago, the battery kept going dead. Charging ok but after a few days.....dead. Out of shear luck one morning working on something, I leaned on the alternator. It was WARM! Cold engine, warm alternator! Turns out the (replacement solid state) regulator was bad, always keeping the field windings energized. Nice and warm.



Maybe your alternator is acting up! Related problem, possible? Just for giggles disconnect it and see if the symptom repeats.

Rich

Sxrxrnr

Your getting warm. This is exactly what we did this afternoon. We had figured that something to do with the running of the engine was setting off the circumstance that was setting up the problem. The problem would not occur when the engine was merely cranked and not started (coil wire pulled) meaning there was no attempt to engage the starter when moving switch from run to off after cranking.

First we throughly checked out the MSD ignition and determined that it was not likely the problem. The thinking was that perhaps it might be the electronic module in the distributor.

Next I disconnected the tach drive. Normally the car has a drive cable off the generator (any C1 owners can dispute this if I am incorrect on this assumption). As the car now has an alternator (not a single wire but regular GM style, which I had said in error earlier) a method was needed to drive the tachometer. The car has this box hidden way deep in the left lower fender. This box has a cable to the tach and wiring to the coil. Converts electronic impulses to drive the tach. Disconnecting this box from the electrical system too had no effect on the problem,,,the starter still engaged at engine shutdown.

The one other hardware component that is active only at engine run time is the alternator. When we disconnected the wiring frpm it, and bingo the problem is gone and the engine shut down normally.

Now here is our theory in a nutshell. The alternator has a wire (brown coded,,,Ron Francis you know) that goes to the fuse panel and then Y's off to the accessory tab on the ignition switch. Disconnect this wire from the ignition switch accessory tab all is well. Disconnect it from the alternator, all is well. We believe but are not electronically certain that this wire from the switch to the alternator is used to bootstrap the alternator at engine start time, to get it to begin charging. We we believe that an alternator needs a kick in the *** from an external charge to wake it up. As is somewhat well known, a car with a totally dead battery cannot be push started as their is no current available to go into the alternator to wake it up. With a generator charging system, you can actually start a cars engine from push starting even without a battery in the car. We suspect that the accessory position tab on the ignition switch is allowing this initial current jolt to the alternator.

The problem is however that this then allows the alternator to back feed current to the switch and with the primitive switch electronics of the C1 design this current at "key turn off time,,,switch run to off" time back feeds and triggers a momentary signal to the solenoid tab which causes the starter to engage.

What we found in metering this switch is that as you turn it from run to off, there is a very brief spurt of current spotted on the meter when it is connected to solenoid tab. Also what I found when the switch is hooked up normal to the car, is that if you are in run position and turn the switch to off position, very, very slowly, the problem of engaging the starter does not occur, however if you turn off switch at normal pace then the starter engages.

Current suspicion is that the later switches (as was in the car before I attempted to install 59 switch) are designed to take care of this problem, as these later cars came stock with alternators and must deal with this possible problem.

All of these findings and guesses are why I will be trying a diode in the brown accessory wire out of the alternator, to allow the kick signal to the alternator, but to preclude a back feed to the switch (which triggers the starter because of the "leaky" internals of the 59 switch) from the alternator. Diodes are basically one way streets for current, that allow only one way flow.

A couple of things I must still do. 1. As noted, the theory is that the alternator requires this kick to get it started. If as in my tests the accessory wire is disconnected from the ignition switch,,where does it get this kick? Either its not getting a kick and is inoperable and is not charging (amp gauge is still out of order and is on my to-do list) because I'm unaware that it is not,,,this is yet to be determined and I will find out tomorrow, or its getting a kick from the "Y" at the fuse panel.
And 2. I will pick up a diode and see if this resolves the problem. This would not be "Bubba fix" if this is the only reasonable solution, IMHO anyway.

Some may ask, why is the accessory wiring used to "kick" the alternator? Best guess is that if you used current directly from battery side, is that you would never be able to shutdown the engine from the ignition switch. The car would be perpetually "hotwired". Perhaps some type of relay would do the job but someone decided that a late model switch would too and it was easier to change switches.

This problem has likely been seen by many. Would be curious if others have installed alternators on their C1's and have they seen this problem. As of now I'm still in problem determination mode and what has been observed so far may be all wrong. Perhaps someone better informed on auto electronics can suggest where our theories may be incorrect and set us to a better path. Will know more tomorrow after I get new tires mounted and get back into this problem.

Anyone bored by all of this, just hit delete or whatever is required to exit this little twilight zone. It is getting curiouser and curiouser for me but it is a very educational challenge.

Again does the "off" position on the C1 ignition switch act as an accessory position that allows use of radio without key in the "ON" position which would more rapidly run down a battery and burn points?

The Corvette Kid

I don't understand why your one wire alt. has two wires. I have owned my 61 for ten years and it has always had a one wire alt. with just one wire to the pos. on the battery with the original ign. switch. Recently I have installed an ls3 engine and a Ron Francis wire harness with a one wire alt. and the original style ign. switch. It starts and shuts off with no problem. Bob

mashinter

No. Off is off.

Off position allows you to remove the key and still start and run the car. I guess that lets the valet drive it, but not get into the glove box and trunk? I never let a valet drive mine!

Frankie the Fink

You can still check alternator output with your accessory wire disconnected at the ignition switch even without a working ammeter. A voltmeter across your battery terminals should read in the range of 13.8V-14.2V if your alternator (and voltage regulator) is working.

With the car running I should add!!!

Sxrxrnr

I had corrected in my last posting the statement that my alternator was a single wire. It is a multi wire GM style.

Only a single wire is visible when looking at the alternator from above, but as I was tracing this problem yesterday, I found a "plug" on the bottom of the alternator (close to the inner fender well so was well hidden from view) which is where the so called "brown" wire to the accessory tab terminates at the ignition switch.

Would be interested in figuring out how single wire as you have differs in wiring from multi wire that I have. The problem gets even more murky.

Sorry for my early misinformation.

The fact that there is no "accessory" position available on these early switches, I suspect that GM likely wired the radio directly to hot wire. So that one must turn off radio separately when leaving car. Is this correct?

Thank you guys
Roger

Frankie the Fink

That is not my understanding....you had to have the key in the ON position to get power to the radio...my '61 is definitely that way.

Frank

rene-paul

Could the intermittent arcing of the negative battery cable upon reconnection be from an original solenoid/point type clock?
brgds
rene

Sxrxrnr

Car has no clock, space is taken by LCD that controls air suspension. I'm suspecting that the momentary arc is either from the MSD distributor or possibly from the amps for the sound system. There are two fairly decent sized ones mounted in the trunk.

A friend told me today, that his 57's radio is wired directly to a hot wire. Says that he must manually turn radio off. This is likely one of the reasons that the later model switch was in the car, to have an accessory position. The 2nd reason, is not to have the starter clang at shutdown. Again if I turn switch from on to off very slowly then all is well. I suspect this is because moving the switch from on, shuts the engine down, therefore the alternator ceases putting out power to the accessory tab on the switch. And when the switch hits the full off position, there is no power leaked from the accessory tab internally to the solenoid circuit. I picked up a couple of diodes today. Hopefully installation of one will solve that problem.

Sxrxrnr

Mysterious problem has been resolved. Placed a diode on alternator ignitor wire and all is well. As suspected this wire was back feeding into accessory position on 59 ignition switch and with its more primitive circuitry when compared to the later switch, caused the starter fire-off at engine shut down time.

This was a good one. A single wire alternator would have been another solution as they do not need an ignitor to kick start them to begin charging.

Only wished that 59 switch had an accessory position to play radio system when engine is turned off. Am considering some type of timer relay circuit to turn radio off automatically after a countdown period of time when engine is shut down. This of course to eliminate possibility of running down battery when radio is wired directly into battery wire,,and you forget to turn it off separately.

Could also wire radio to ignition tab of ignition switch, but this would mean that ignition switch must be in "on" position to play radio.

Any suggestions?