starter issues again

[lunarhighway]

i was 15 minutes late this morning at work cause of an annoying problem with the starter. the weird thing is it's the second time in a few months i've had this problem so i'd like to figure out what's causeing it.

here's what happens

i get in the car, turn the key in the ignition, but use my own rigged up starter button for the actual starter .
the button basically overriders the last 2 connections in the key switch to route power to the starter, it takes it's power from the lines normally intender for the lighter as i don't use it, and it's only on when the ignition is on, so you can't start the car without the key. works without problems for more than half a year now or so.

the starter motor fires up, but it keeps running, even when the engine and even the ignition is off... so i get out disconect the battery.... everything stops.... i reconnect it, and the starter starts whining again.

thas has happened twice now, and perhaps coincidental,always after my dad had put the car in the garage when he left for work an hour early so the windows would defrost. nice thing to do of him.
this means it started fine an hour before, and most likely with the key.

when it happened the first time i figured it might have to do with my custom start button wireing so i unhooked it, but that didn't solve things.

it turned out the key switch in the ignition was burned trough and had apparently made a shortcut between the starter and the ignition position. my dad assured me that this was a common defect. fortunately my dad was just parting out his rusty old ascona and the switches are identical so it was an east fix.

however this morning the same thing occurs... this time i figure the new contact must have been burned trough as well, so i remove all the paneling in the hopes of cutting the key switch line so i could still start the car with the button as a stop gap solution, however the contact looks fine. i switched it a couple of times with a screwdriver and it felt ok, when i put everything back things suddenly behaved again.

so what do you think? is this the starter switch starting to wear out... wich would be somewhat odd as my dad never had any problems and i alsways use my start button so the contact is't used for powering the starter motor...

should i revise my button setup somewhat? or should i just desconnect the actual key switch alltogether, and only use the button?