'99 Grand Am - Problems connected or coincidence?

Yesterday my driver-side window wouldn’t roll down (when all others worked just fine), the fuel gauge started this new thing where it goes drastically up or down when I’m idling for at least 30 seconds (but when I start moving again it goes back to where it was), and on my last fill up I noticed I got drastically lower gas mileage (17 mpg instead of the usual 24). I haven’t required another fill up yet so I’m not sure about the gas milage, but the other two problems are consistent.



My parents bought my car new in 1999 and I inherited on my 16th birthday. Up till now, it’s been a great little car requiring minimal repairs, so it’s possible these things just all need to be replaced at the same time, but it’s weird that they all occurred, or at least I noticed them all for the first time, in the same driving session. Other odd problems my car has is the infamous clicking noise from what I assume is a bad turn signal connection and my cruise control button won’t stay clicked into place to allow cruise control to stay on without my finger pressing it the whole time I drive (I actually drove a whole 12-hours like that!) Let me know if you’ve got anything to tie this occurrences together or if you think I should just accept the fact that my car is getting old and this is the beginning of the end.

While it’s possible that some wires have gotten a little too intimate, I don’t think that this is the case. One would start the troubleshooting with one circuit at a time. A test light, or a multimeter, and the wiring circuit diagrams would be the first step in finding the fault(s).
This minor stuff is not the end. If the check engine light is on, let an auto parts store scan (free) for the trouble codes. Then, bring those codes here for comments (some helpful, hopeflly).

I think it’s called old age and coincidence. My 2000 Blazer is having similar issues. Just a couple of suggestions.

Try spraying the window switch with CRC Electrical contact cleaner. If possible remove the switch housing from the door and spray the back of the switch.

The multifunction function switch is a known problem with Grand Am’s, google “Grand Am Multifunction Switch”. I replaced the multifunction switch on my 2000 Blazer about 3 years ago. The switch is ~$200 and I’m guessing labor would be around $200-$300. Try spraying some contact cleaner into the base of the switch at the steering column. It stopped the clicking on my switch for a few days, perhaps you will be luckier.

The gas gauge on my Blazer stopped working 3 years ago. When the truck is in neutral the needle bounces around, putting it in Drive the needle settles down but is not accurate. I just fill up the tank and keep track of the miles. It may be the beginning of the end of your gauge.

As for the mpg, I check mine every 3 or 4 tankfuls of gas. I wouldn’t get too upset of one tank of gas.

Good luck,

Ed B.