1997 Chevy Blazer Ignition problem


I was told that you guys really know your stuff, so here it is. I have a 1997 Chevy Blazer 4X4 V6. Ever since I purchased this vehicle it has stalled frequently out of the blue. All power goes out completely, and then returns. Over the past couple of years I have narrowed it down to something in the ignition. If I bang on the key while it is inserted into ignition, the power will return; hence allowing me to start the vehicle again. Once in a while the key will also get stuck in the ignition, and then my truck will not shift. I had AutoZone put the code reader on my Blazer, and it said that I have a ground fault in transfer case D. Is this all related to one problem, or am I having mutiple problems? When the key is not stuck and the power is on, everything seems fine. I would appreciate any input you might have for me on this issue, and would like to know if these are common problems? If so, what should I do to fix this beast? Any other Ideas?

Thank you.

Mark Russell


Your problems seem to be consistant with a faulty ignition switch. I am refering to the electrical portion not the key and tumblers. If the switch fails while driving the motor will die and you will lose power to everything. Also since the solenoid that releases the key when the trans is in park runs through the ignition switch that could explain the stuck key.
As far as the ground fault in tranfer case D I think that is a seperate issue.


Thanks for the information I apprieciate it very much.
How would that explain the car not shifting when the key is stuck?


That also doesn’t really make sense to me because sometimes on initial start-up there is no power either, and when I hit the key it gets power. If it was electrical, I would think hitting the key wouldn’t really matter.


That depends on what you mean by shifting. If you mean you cannot get it out of park it is because there is an interupt in the power from the ignition switch to the interlock relay.
A failure in the ignition switch can cause the vehicle not to come out of park, the vehicle solenoid on the column to not recognize the vehicle is in park therefore not allowing the switch to turn off, etc…
As far as banging on the key you must remember the ignition switch is located directly on the end of the lock cylinder. The impact will directly effect the switch forcing the internal points to move and make contact again.
Hope that helps.


Here are a couple of pictures that show the relationship of the lock cylinder and the ignition switch. Maybe they will help you to picture why hitting the key effects the switch.


That was very informative, but by shifting I mean the car is stuck in second gear during driving. It will manually shift, but will not go through the gears automatically during driving; this happens only when the key is stuck in the ignition. It shifts fine when the key is not stuck. This has been this way for two years.


I cannot explain that unless you have a voltage drop to the TCM (Trans control module) do to the faulty ignition switch.

You may also have two seperate problems. The code for the ground fault could be causing the shifting problem. However, the ground fault could be linked back to a voltage drop at the ignition switch.



Thanks so much for all your proffesional advice. I will definately look into having my ignition switch replaced, and then take it from there as far as the shifting is concerned. Your awesome, thanks.


Your welcome. Please let us know how things turn out.