JETMECH

Old reliable finally broke and I can't seem to fix her. I'm starting to lean more toward something in the electrical system now but I will run through on what I have checked and let the experts decide on if I missed something or if they know what it might be. For starters, it a 93 SC2 with a five speed. It just rolled over 260k on the odometer. When you turn the key to start it, nothing happens. No sound or anything. Everything else in the car works fine. It just acts like the starter is not getting power. I put a good battery in it (out of my other car just to make sure its good) and cleaned all of the terminals and grounds. The clutch switch is adjusted correctly and making contact. I removed the starter and had it tested at O'reilly's and it checked good (its only about 5 years old). Theres no blown fuses and the car runs fine when you get it push started. I know I read on here somewhere that power goes from the ignition switch to the clutch switch and then to the starter. Could someone line me out on how this circuit operates? Thanks in advance guys because you've helped me with problems in the past.

nutjob

You're right, the clutch safety switch is in line with the ignition switch before the starter to prevent the inept from starting in gear with the clutch engaged. Here's one way to isolate this; jump out the clutch safety switch for now and/or while you're down there use a multimeter to check for 12v on one of the terminals while someone turns the ignition key to START. The START (12v) signal/voltage leaves the ignition switch, goes through the clutch safety switch, and ends up as the purple power/signal for the starter solenoid terminal. You should see 12v at one side of the clutch switch and when the clutch is depressed the 12v should be on the other terminal where it goes to the starter solenoid. Once you bypass (jump out) the clutch switch it will be easier to check for the 12v START signal at the starter solenoid small terminal where the purple wire is attached. Check for 12v there by repeating the ignition key sequence; turn the key to START and you should see 12v at the small terminal of the starter solenoid. If you don't see 12v then the problem is upstream and if you see 12v at the terminal the starter should at least 'click' loudly or the starter run immediately. Make sure the large battery connection isn't loose, the battery cable connections aren't loose/corroded at the battery posts and the ground connection also. There was a time with battery side post terminals made by AC DELCO that a weak positive terminal cracked leaking acid onto the battery cables, slowly corroding the wire strands inside the heavy insulator eventually destroying the connection. The exterior looked fine until it was removed and closely examined before discovering the damaged cable. Some owners paid several hundred dollars for Saturn to find this simple starting problem, replacing the positive cable and battery.

JETMECH

I went a head and stripped back the insulation on the positive cable and its fine. Same with the negative. Also I tried jumping the clutch switch and nothing. Unfortunately my multimeter is at work and I wont be able to check it so here comes another day of push starting it (unfortunately my wife needs the blazer). I guess I can check it on my lunch break. So if the yellow wire is not producing 12 volts then I guess I should check it at the output of the ignition switch on the column. This would definitely isolate the problem. If there is a problem, is there anyway to splice 12 volts into the yellow wire down at the clutch switch such as a spring loaded momentary switch and bypass the probelm (providing I find it to begin with). Wish me luck...I think I'm going to need it.

nutjob

As far as not having a meter to use you can make up a 12v test lamp with a pair of alligator clips soldered to the bulb, voila! You now have a voltage tester. Clip one lead to ground and use the other clip to probe for 12; any light indication means you have 12v.

The clutch switch can be bypassed by running one wire to one of the terminals and the other end to the other terminal. Testing for proper switch action with a test light just involves clipping one lead to the frame ground and probing with the other lead on the switch terminals; once the ignition key is turned to START one side of the clutch switch should light up and pressing the switch, as in depressing the clutch pedal down to the floor, should allow 12v to the other terminal. From there the 12v should travel to the small purple wire on the starter solenoid to energize the solenoid that turns on the starter motor. No voltage (light) at the clutch switch means that the 12 v START signal isn't leaving the ignition switch in START mode. Then you'll have to troubleshoot the ignition switch and you can still use the test light instead of a meter. After all, you're only looking for 12volts as part of the starting circuit. The electronics uses 12v and 5volts.

JETMECH

I ended up checking for voltage at the starter and found it. I removed the starter again and out of curiosity pulled the rear cover off. Least to say I was amazed at what I found. The two spring loaded brushes were no more. The only thing left was the wire that actually attached the brushes were caught under the shims that go on top of the brushes that insulate the spring from them. This would explain why it was intermittent. I just can't believe it even worked. I threw another starter on it which seemed to fix the problem but the intermittent starting is what had me perplexed. You can't beat checking for that voltage. It led right to the problem. Thanks for the help.