QuestionQUESTION: Hi Dick,
We have corresponded in the past, and your expert advise has been very helpful and valuable.
My problem involves the ignition on my 64 Bonneville. Today, when I attempted to start the car after it had sat in the garage for a week, it needed to be cranked several times before starting (not unusal). After it started, I noticed smoke coming from the key hole, and from the back of the ignition under the dash. I immediately turned it off, waited a few seconds, tuned the switch to the on position, and once again, it smoked and I detected a slight red glow from the ignition, behind the dash. After letting things cool down for a couple of minutes, I started it again, and there was no sign of smoke, or any electrical burning smell. An hour later, I tried it again, and no problem was encountered. Does this indicate that the ignition might be defective, and require replacement, along with the wiring harness, or is it what can be expected when I try to crank numerous times? Your thoughts and suggestions are greatly appreciated.
Thank you.
Vince Carbone
ANSWER: Hi, Vince;
It is easy to say the obvious, that you have a very serious problem with either the ignition switch or the wiring that is attached to it.
My guess, (but it is only a guess, based on experience, but without examining the area myself,) is that the problem is a bare area on a wire which is sometimes touching a grounded metal piece in the area behind the ignition switch.
You should be able to see the damage caused by this by looking with a mirror and a flashlight for scorched parts or wires in the area.
Do not try to use the car until this is diagnosed and fixed - in particular, disconnect one battery cable (it doesn't matter which one) until you track down the offending item.
If I read your question accurately, the second time you turned on the key, you did not try to start the car. If this is correct, (and the switch is held firmly in the dash without moving when you turn the key) yet you still saw smoke, we can narrow down which wire it has to be - namely it is either the wire on the "I" terminal or the one on the "ACC" terminal.
If I have mis-understood what you said, and in fact the smoke only occurred when you crank the engine, the wire that is shorting to something grounded has to be the one on the "S" terminal of the switch.
If the switch is loose in the dash, however, we cannot tell which wire it is without inspection, but the most likely culprit is the "B" wire. These letters are on the back of the switch, by the way. The "B" wire and the "S" wire will be larger than the other two, probably, and the "S" wire will probably be the one on the terminal that protrudes furthest out behind the dash from the switch mounting surface.
In any case, once you do your inspection of the area and perhaps find the offending wire, you will need to remove the connecting wire harness from the back of the switch in order to get it out far enough that you can replace the offending wire, or at least tape it up with electrical tape to prevent it making contact with any metal part again.
It is much easier to do this sort of work if you first remove the ignition switch from the dash and let the whole thing hang down under the dash where you can get a good look at the switch, the wiring, and the clips that hold the wiring to the switch.
In case I am wrong and the switch itself is the culprit, that will be obvious when you get the switch out where you can see it, because the plastic will be melted and charred where the defect occurred.
Be sure that you disconnect that battery cable right now, and leave it disconnected until you find and fix the problem!
Dick
---------- FOLLOW-UP ----------
QUESTION: Dick,
You understood me correctly....the smoking occurred not only when I cranked the engine, but when the key was turned to the on position. I probably will not be able to address the issue until next weekend, but I will certainly take your advice and disconnect one of the cables ASAP. I'll let you know how things turn out. It's odd how this problem just popped up. As always, I GENUINELY appreciate your expertise.
Vince Carbone
ANSWER: OK, Vince, I'll wait to hear back from you.
If the ignition lock is firmly held in the dash, the problem pretty much has to be on one of the two wires I listed.
Dick
---------- FOLLOW-UP ----------
QUESTION: Hi Dick,
I took your advice and disconnected one of the battery cables. However, before I did this, I couldn't resist doing the following: I inserted the key, turned it to the "on" then "off" position 3 or 4 times without seeing or smelling smoke. On the 5th time, smoked occurred as soon as it was in the "on' position. With that in mind, do you still think that it is a bare wire touching ground, or do you think the switch might be bad? I wonder why it "smokes" randomnly. Also, the switch appears to be fairly tight, but can be easily loosened by hand.Mayne it is not as tight as it should be. Could that be the problem? Also, I used a mirror and flashlight, per your instructions, and saw no signs of charring. Over the weekend, I plan to remove the switch. It appears as if all I have to do is unplug it from the back, and release the clips. Your comments are most appreciated!
Thanks, again.
Vince
AnswerI can only go with the physics involved here. To produce smoke, something is getting very hot. To get hot, it takes enough current flowing through a connection that has significant resistance. It is possible that this is happening inside the switch, but the current has to be going somewhere, and if nothing is on in the car when this is happening, it almost certainly means the current is flowing directly to ground, or possibly through some very low resistance to ground. The connections to the switch do not include a ground connection, so if the errant connection is occurring inside the switch, the current has to be somehow getting to ground via one of the wires on the switch. Most of the wires on the switch will make something happen when they get 12 volts on them (the engine cranks if it is the "S" wire, the ignition turns on if it is the "I" wire, the accessory buss comes on if it is the "Acc" wire etc. If you have power windows or seats, it is remotely possible that some problem in one of those accessories is drawing enough current to make the switch smoke, but that would happen every time, not intermittently.
The bottom line is, you need to take the harness off the switch (yes, just lift up the clips), and also remove the switch, and inspect everything on both items until you find the "smoking gun". Something is burning somewhere- your nose will tell you where!..
Let me know what you find!
Dick
