[ggcatt]

Our 2000 4WD 4dr Tracker has the A/T switch. I believe it adjusts the shift points on the automatic transmission so that you can get more power (and lower fuel efficiency) when pulling a trailer. "P" is power, "N" is normal. We never use ours, just leave it in "N". Ours has a 3 speed with overdrive (4 speeds total) and runs about 2800 rpm at 70 mph, so I would say you are not shifting into overdrive. Ours has a small switch on the side of the shifter lever that uncouples the overdrive when pressed in. A light comes on in the dashboard in that condition as well. Now, with your A/T switch unhooked, you may also have the overdrive switch unhooked. I'd check this out.