I have been tolerating this 90 Reatta for a while, and thought I was making progress, but suddenly this bad boy has resumed its old ways.
There are two basic problems (besides the obvious...that it was made in the dark ages of automotive electronics, and Buick engineers tried to do too much with too little)
First is the security key problem. More often than not, it will not start on the first try. It will not crank over, nothing. I had had the security system bypassed, and it was working perfectly, but suddenly it is back as before. I will have to check the resistor bypass, and see if that is the issue. This one, I think, is easy to solve.
The second issue is harder. I have a new battery, new cables, good starter and good alternator. BUT, if I leave the car standing for a few days, I come back and the battery may (or may not) be flat. I checked the residual current and after the systems reset (within a few seconds) the current drops to 30 ma. But I suspect that something is activating periodically AFTER shutdown, and drains the battery with time.
I can start the painful process of removing the connections to the wiring 'tree' one thing at the time, but this could take forever. Intermittent problems are a bitch, aren't they?
Any suggestions appreciated. (Just listening to my tale of woe is also appreciated)