I have a 1996 sw2For the last few months I have been having this problem. Sometimes the car will start and sometimes it won't When it won't start, I will wait a day or two and it starts fine for a couple days then it starts all over.When it's not starting, I turn the key all the way, but nothing happens like when the battery is dead, except that I hear one of the relays clicking below where the heater controls are. I have replaced that relay and the one under the hood and it didn't make a bit of difference. The last two times it happened I had it towed to a garage and they always seam to be backed up and don't look at it for a day or so and then it winds up starting and they tell me they can't do anything/test anything because whatever the problem may be it will show up as ok since it's starting fine. So I am not sure what the problem is and would really like some idea? I was thinking it was the ignition switch, but I can hear the relays click so I figure it's making the connection and sending the power, but I don't know if that matters or not? Anyway any help would be appreciated.Thank you.
Edited by: sw2cam

 

Check for corrosion inside the positive battery cable and where the cable mounts to the battery. Its very common for cars built at time to have their original AC Delco batteries leak fluid through the positive terminal and into the cable, causing internal corrosion. But it can happen to other year S-Series as well. I've seen it in 1991's through 2002's