no ignition spark but runs fine if hotwired at starter

[Bair]

'93 MX-3 V6 no interesting mods or alarm systems other than an aftermarket radio. Bought the car last month and seemed to run fine but the guy selling it had replaced one of the rusted out engine brackettes and had the second one ordered. I was out of town anyway so he replaced the second engine mount but when I picked up the car the key would not start it. You turn the key and the dash lights come on but the engine doesn't spark. By reaching down to the starter from under the hood the car hotwires perfectly with a screwdriver. The guy said that this happened once before and it was the starter switch and he ordered one. Installed the new starter switch but problem is still there. I should be getting hold of a multi meter today and figure I better check the fuses but I'm wondering if this might be a grounding problem or if there could be a rusted wire or bad connection causing the problem. Of course since I know very little about mechanics and nothing about Mazda's I could be going down a completly wrong track but looking through the forums online it sounds like in many cases people have had similar issues and replaced modulators and starters and all sorts of things to get back to basic wiring so I thought I would start there. Please help! Car runs pretty well when I get it started but reaching under the hood everytime I have to start the car is less than ideal in 100+ Texas heat!

[wytbishop]

Power goes directly from the battery, through the iginition switch, through the interlock switch and to the postive side of the starter solenoid. If the switch is not at fault then 999 out of 1000 times the starter solenoid is. The other 1 time it's the interlock (clutch switch on MTX).

[Bair]

Thanks this is helping me clarify and follow the problem. I went down to the auto craft center yesterday and two of the guys seemed to think that it is the neutral safety switch is that the same as the interloc switch? How is the best way to check if it is the starter solenoid?

[wytbishop]

http://www.mx-3.com/manuals/showimg.php ... /G-034.gif" onclick="window.open(this.href);return false;

When the ignition switch is in the start position, there should be at least 8volts at the terminal labelled "S" in that diagram. If there is 8V, the power is there but the solenoid isn't closing probably because the winding in the solenoid is fried. If there is not 8V, something is preventing power from reaching the solenoid...probably the neutral safety switch, but could also be a broken wire in the harnes though that would be extremely rare.

[Ryan]

I've also had issues with the starter grounding itself out. If all the power to the starter is correct, then get a junk yard replacement. They don't seem to go often.

[Bair]

Thanks for the help. Key works again... there was a lot of terrible corrosion at the park/neutral switch... cleaned it all off and now the ignition is working. Checked the starter out and it seems to be fine for now.