Clean contacts on ignition switch 97 Regal GS

[C5Z06]

I have the ignition switch plastic box out and want to know if anyone has taken it apart to clean the contacts. Traced blower speed problem to switch. There are 6 small springs held in by top plastic cover. The top half of switch can be removed but I'm afraid the mechanism may have more springs inside and I may not be able to get it back together. Has anyone done this successfully? bnaylor may know as I've read some of his posts and he has experience. TIA for any help.

[BNaylor]

Oh yes thats a fun one. Not really though. But you're in luck. Good luck.

All of these things get power through the ignition switch, specifically the RUN terminal (when the key is in the 'RUN'position), which is an orange wire on the bottom of the switch. When the problem was occurring I was getting fluctuating voltage on the RUN terminal (measured with a multimeter), jumping anywhere from .5 to 10, but usually hanging around 1 or less. When it was working properly the voltage read normal battery voltage, 14 or so. When the problem was occurring and I jumped that terminal to an always hot terminal everything came on and worked perfectly. So great, it's something in the switch.

Being the curious type I took the switch apart, figuring at worst I'd have to buy a new one... Would you believe the problem is carbon buildup a little larger in size than a pinhead? It's actually kind of nifty how they made this switch. When you turn the ignition key it turns a spring loaded plastic shaft in the switch. On this shaft are 6 lobes sort of like a camshaft, though not as tall. Each lobe has a rocker-shaped piece of metal spring loaded to rest on the lobe. As the shaft is turned when you turn the key it causes the various rockers to move out due to the lobes and make connections with terminals laid out by either side of the shaft. So, turn the key to RUN and the shaft turns moving the rocker out to make connection with the RUN terminal.

The beauty of this mechanism is how it can turn on or off certain terminals depending on how far the key is turned. An example of this is when you turn the key from RUN to START. The lights and fan go off because the RUN rocker is coming back down off the other side of the lobe as the START rocker goes up and makes its connection to send voltage to the starter relay.

It is this on-off-on action of the RUN rocker every time you start the car that I believe causes the problem. At the point where the rocker makes the connection to the terminal some arcing is taking place due to the volts and amps being drawn, causing a carbon buildup at that point. The more carbon that gets built up the worse the connection gets. Since the fan draws its voltage through this terminal more arcing is taking place if the fan is running when you turn the key. As a result there is more carbon buildup as compared to the other rockers that had very little or none at all since they do not have such high voltage/high amp devices to feed. I cleaned off the carbon with a soft wire brush and juggled around the rockers so the relatively 'unused'ones found themselves switched with the 'overused'ones.

I have not had a problem since then. Since the fan is probably the biggest contributor to the arcing and resultant buildup I am making a point of it to have the fan off when I turn the car on or off. This should help keep this problem from coming back for a great while longer.

[C5Z06]

Thanks for your input bnaylor. I had already taken the switch apart and I think I got it cleaned and put back together correctly. What's even worse about the fan circuit is the load is inductive which makes it more prone to arcing since the inductance tries to keep the current flowing in the circuit. I am an EE with 40 years experience designing electronic circuits. I'll report back as to whether I fixed the problem or not. It took me a while to figure out how the spring on the plastic cam fit but think it can only go one way. A couple of the contacts had carbonized and I was able to remove it with a fine sand paper carefully so as not to remove the silver plating. It appeared to be silver and that is the best conductor. Even silver oxide (brown) unlike copper oxide (green) is a good conductor. This is a high quality switch in a rugged application. I would have added a snubber or other arc suppression components to the inductive loads that are switched. Never use emory paper or other material that have conductive particles to clean contacts, commutators etc. Enough soapbox. I'll reconnect battery and try it later today.

[C5Z06]

O.K. Turned switch on everything was ok until I went to the crank position. Heard a snap and think spring came off the shaft of the plastic cam or I broke the tang that the spring rests against. I may just leave it rather than disassemble it. The original problem with the blower motor speed appears to be fixed. If you turn it back to the run position after starting everything is ok. I'm going to run it this way and see if it causes any problems. There are detents in the plastic cam that align it via a spring loaded pin in the bottom and that is working to place the cam in the correct position. You have to manually place the switch in the correct position but that is easy.

[BNaylor]

Sounds good. At least it was a good learning experience. If all else fails at least you'll be able to replace the ignition switch and harness with a new one in a timely manner. Good luck.

[C5Z06]

Thanks again for your input. I appreciate it. Don't hesitate
to email me with questions about problems I've solved on this
or many other vehicles I've owned. I've extensive experience
with the brakes on the Regal GS (They were too light duty from
GM). I installed the 12" rotors and proper caliper brackets to solve
the warped rotor problems many see. I have had 4x4 truck problems
with 99 Sierra that may be of help and I've got a 2003 Z06 Vette too.
I'll check the site occassionally too to see if I can offer help in areas
where I have knowledge.
Fred

[C5Z06]

OK guys. I got my used switch from Ed Morad today. I disassembled it and again the spring released and flew out. Here is the good news I figured out how to reassemble the switch and spring so that it works like new. You have to preload the spring with the cam so that the straight tang on the spring is at 12 o'clock while the bent tang is hooked into the bottom half which has a slot for it. There is a groove in the top half housing that the straight tang slides in. It is easy to do with the right size flat blade screw driver. While I preloaded the spring and held the cam against the lower half of the switch my wife snapped the top half on and it works perfectly. I hate to give up on anything. I cleaned the contacts so I've got a good spare if the one in the car without the spring working properly shows any problems. Thanks again for the encouragement and help. I'm amazed and glad that other people on this site had tackled and solved this problem.