Date: Thu, 24 Feb 2000 11:35:40 -0800 From: TimeRangernopsam.com Subject: Re: Starter & electrical system... describe operation?
On Thu, 24 Feb 2000 11:20:35 -0500, Scott I. Remick <scottnopsamuteralt.com> wrote: > >Well the problem has never gone away, and in fact seems to be getting >worse. So I need some more help. > >Can someone describe in detail the way the starter works, how electricity >gets to it from the key switch, what goes where, and what happens on the >three post contacts on the starter? As much info as you can supply would >be great... I figure if I can understand it backwards and forwards, I can >maybe figure out eventually what's failing when it happens. > >I have an '84 Saab 900S. Here's what happens: occasionally, you'll go to >start the car and the starter won't budge. You have plenty of >electricity to power every other part of the car (lights come on and so >on), and you'll hear the fuel pump run for a moment, and the clicking of >relays elsewhere... but not a sound from the starter. It SEEMS to happen >more frequently when the car is warm. Let it sit for a while, and it >will start. Sometimes though, even when it DOES start, there's a >abnormal 2-3 second delay after turning the key before you hear the >starter even turn. Maybe this is a hint...? > >When it doesn't start... a second or two after holding the key turned you >start to hear a clicking coming from some device on the left (driver's) >side of the engine compartment. I've located the device, but I don't >know what it does. Other than the fuel pump, these are the only sounds >you'll hear when the car refuses to start. > >I've replaced the starter several times... that's not it. And lately >I've never been able to get it to happen for a service tech. Inevitably, >hauling one down magically causes the car to start up just fine. > >So anyhow... I'm looking for a nice detailed description of how the >starter/ignition operates (especially what happens on those three >contacts and the ignition switch), so I can go at this with a multimeter >and track down the problem. Thanks! Scott, it sounds more like a battery problem than a starter problem. Clean the battery terminals and Keep Them CLEAN! While you may have "good" lights, and all of the accessories, a dirty battery connection will not allow enough current flow to turn the starter. The starter requires more amperage than all of the other electrical components combined. The most common problem is a dirty ground/negative/earth connection. Remember - electrons flow from negative to positive. If the negative side is dirty/corroded/loose, the current has trouble leaving the battery on its way to the starter relay. -- "Our eyes and hands and feet will give us the same assistance in doing mischief as in doing good; but it would not therefore be better for the world, that all mankind were blind and lame. Arms are not to be laid aside by honest men, because carried by assassins and ruffians; they are to be used the rather for this very reason." -George Campbell